Should be fixed now with this commit:
drivers/iio: Fix MODULE building · analogdevicesinc/linux@9a6fef6 · GitHub
Thanks for pointing out.
P.S. We always accept also patches
-Michael
michael@mhenneri-D04:~/devel/hdl/github-linux-build/linux$ make modules | grep iio
CC [M] drivers/iio/adc/ad7266.o
CC [M] drivers/iio/adc/ad7291.o
CC [M] drivers/iio/adc/ad7298.o
CC [M] drivers/iio/adc/ad7476.o
CC [M] drivers/iio/adc/ad7791.o
CC [M] drivers/iio/adc/ad7793.o
CC [M] drivers/iio/adc/ad7887.o
CC [M] drivers/iio/adc/ad799x.o
CC [M] drivers/iio/adc/cf_axi_adc_core.o
CC [M] drivers/iio/adc/cf_axi_adc_ring.o
CC [M] drivers/iio/adc/cf_axi_adc_ring_stream.o
LD [M] drivers/iio/adc/cf_axi_adc.o
CC [M] drivers/iio/adc/ad9467.o
CC [M] drivers/iio/adc/ad9361.o
CC [M] drivers/iio/adc/admc_adc.o
CC [M] drivers/iio/adc/admc_speed.o
CC [M] drivers/iio/adc/admc_ctrl.o
CC [M] drivers/iio/adc/ad_adc.o
CC [M] drivers/iio/adc/ad6676.o
CC [M] drivers/iio/adc/cf_axi_fft_core.o
CC [M] drivers/iio/adc/cf_axi_jesd204b.o
CC [M] drivers/iio/adc/cf_axi_jesd204b_v51.o
CC [M] drivers/iio/adc/cf_axi_jesd204b_gt.o
CC [M] drivers/iio/adc/xilinx-xadc-core.o
CC [M] drivers/iio/adc/xilinx-xadc-events.o
LD [M] drivers/iio/adc/xilinx-xadc.o
CC [M] drivers/iio/amplifiers/ad8366.o
CC [M] drivers/iio/dac/ad5360.o
CC [M] drivers/iio/dac/ad5380.o
CC [M] drivers/iio/dac/ad5421.o
CC [M] drivers/iio/dac/ad5624r_spi.o
CC [M] drivers/iio/dac/ad5064.o
CC [M] drivers/iio/dac/ad5504.o
CC [M] drivers/iio/dac/ad5446.o
CC [M] drivers/iio/dac/ad5449.o
CC [M] drivers/iio/dac/ad5592r.o
CC [M] drivers/iio/dac/ad5592r-base.o
CC [M] drivers/iio/dac/ad5593r.o
CC [M] drivers/iio/dac/ad5755.o
CC [M] drivers/iio/dac/ad5764.o
CC [M] drivers/iio/dac/ad5791.o
CC [M] drivers/iio/dac/ad5686.o
CC [M] drivers/iio/dac/ad7303.o
CC [M] drivers/iio/frequency/ad9517.o
CC [M] drivers/iio/frequency/ad9523.o
CC [M] drivers/iio/frequency/ad9548.o
CC [M] drivers/iio/frequency/adf4350.o
CC [M] drivers/iio/frequency/adf5355.o
CC [M] drivers/iio/frequency/cf_axi_dds.o
CC [M] drivers/iio/frequency/cf_axi_dds_buffer_stream.o
CC [M] drivers/iio/frequency/ad9122.o
CC [M] drivers/iio/frequency/ad9144.o
CC [M] drivers/iio/gyro/adis16080.o
CC [M] drivers/iio/gyro/adis16130.o
CC [M] drivers/iio/gyro/adis16136.o
CC [M] drivers/iio/gyro/adis16260.o
CC [M] drivers/iio/gyro/adxrs450.o
CC [M] drivers/iio/imu/adis16400_core.o
CC [M] drivers/iio/imu/adis16400_buffer.o
LD [M] drivers/iio/imu/adis16400.o
CC [M] drivers/iio/imu/adis16480.o
CC drivers/iio/adc/ad6676.mod.o
LD [M] drivers/iio/adc/ad6676.ko
CC drivers/iio/adc/ad7266.mod.o
LD [M] drivers/iio/adc/ad7266.ko
CC drivers/iio/adc/ad7291.mod.o
LD [M] drivers/iio/adc/ad7291.ko
CC drivers/iio/adc/ad7298.mod.o
LD [M] drivers/iio/adc/ad7298.ko
CC drivers/iio/adc/ad7476.mod.o
LD [M] drivers/iio/adc/ad7476.ko
CC drivers/iio/adc/ad7791.mod.o
LD [M] drivers/iio/adc/ad7791.ko
CC drivers/iio/adc/ad7793.mod.o
LD [M] drivers/iio/adc/ad7793.ko
CC drivers/iio/adc/ad7887.mod.o
LD [M] drivers/iio/adc/ad7887.ko
CC drivers/iio/adc/ad799x.mod.o
LD [M] drivers/iio/adc/ad799x.ko
CC drivers/iio/adc/ad9361.mod.o
LD [M] drivers/iio/adc/ad9361.ko
CC drivers/iio/adc/ad9467.mod.o
LD [M] drivers/iio/adc/ad9467.ko
CC drivers/iio/adc/ad_adc.mod.o
LD [M] drivers/iio/adc/ad_adc.ko
CC drivers/iio/adc/admc_adc.mod.o
LD [M] drivers/iio/adc/admc_adc.ko
CC drivers/iio/adc/admc_ctrl.mod.o
LD [M] drivers/iio/adc/admc_ctrl.ko
CC drivers/iio/adc/admc_speed.mod.o
LD [M] drivers/iio/adc/admc_speed.ko
CC drivers/iio/adc/cf_axi_adc.mod.o
LD [M] drivers/iio/adc/cf_axi_adc.ko
CC drivers/iio/adc/cf_axi_fft_core.mod.o
LD [M] drivers/iio/adc/cf_axi_fft_core.ko
CC drivers/iio/adc/cf_axi_jesd204b.mod.o
LD [M] drivers/iio/adc/cf_axi_jesd204b.ko
CC drivers/iio/adc/cf_axi_jesd204b_gt.mod.o
LD [M] drivers/iio/adc/cf_axi_jesd204b_gt.ko
CC drivers/iio/adc/cf_axi_jesd204b_v51.mod.o
LD [M] drivers/iio/adc/cf_axi_jesd204b_v51.ko
CC drivers/iio/adc/xilinx-xadc.mod.o
LD [M] drivers/iio/adc/xilinx-xadc.ko
CC drivers/iio/amplifiers/ad8366.mod.o
LD [M] drivers/iio/amplifiers/ad8366.ko
CC drivers/iio/dac/ad5064.mod.o
LD [M] drivers/iio/dac/ad5064.ko
CC drivers/iio/dac/ad5360.mod.o
LD [M] drivers/iio/dac/ad5360.ko
CC drivers/iio/dac/ad5380.mod.o
LD [M] drivers/iio/dac/ad5380.ko
CC drivers/iio/dac/ad5421.mod.o
LD [M] drivers/iio/dac/ad5421.ko
CC drivers/iio/dac/ad5446.mod.o
LD [M] drivers/iio/dac/ad5446.ko
CC drivers/iio/dac/ad5449.mod.o
LD [M] drivers/iio/dac/ad5449.ko
CC drivers/iio/dac/ad5504.mod.o
LD [M] drivers/iio/dac/ad5504.ko
CC drivers/iio/dac/ad5592r-base.mod.o
LD [M] drivers/iio/dac/ad5592r-base.ko
CC drivers/iio/dac/ad5592r.mod.o
LD [M] drivers/iio/dac/ad5592r.ko
CC drivers/iio/dac/ad5593r.mod.o
LD [M] drivers/iio/dac/ad5593r.ko
CC drivers/iio/dac/ad5624r_spi.mod.o
LD [M] drivers/iio/dac/ad5624r_spi.ko
CC drivers/iio/dac/ad5686.mod.o
LD [M] drivers/iio/dac/ad5686.ko
CC drivers/iio/dac/ad5755.mod.o
LD [M] drivers/iio/dac/ad5755.ko
CC drivers/iio/dac/ad5764.mod.o
LD [M] drivers/iio/dac/ad5764.ko
CC drivers/iio/dac/ad5791.mod.o
LD [M] drivers/iio/dac/ad5791.ko
CC drivers/iio/dac/ad7303.mod.o
LD [M] drivers/iio/dac/ad7303.ko
CC drivers/iio/frequency/ad9122.mod.o
LD [M] drivers/iio/frequency/ad9122.ko
CC drivers/iio/frequency/ad9144.mod.o
LD [M] drivers/iio/frequency/ad9144.ko
CC drivers/iio/frequency/ad9517.mod.o
LD [M] drivers/iio/frequency/ad9517.ko
CC drivers/iio/frequency/ad9523.mod.o
LD [M] drivers/iio/frequency/ad9523.ko
CC drivers/iio/frequency/ad9548.mod.o
LD [M] drivers/iio/frequency/ad9548.ko
CC drivers/iio/frequency/adf4350.mod.o
LD [M] drivers/iio/frequency/adf4350.ko
CC drivers/iio/frequency/adf5355.mod.o
LD [M] drivers/iio/frequency/adf5355.ko
CC drivers/iio/frequency/cf_axi_dds.mod.o
LD [M] drivers/iio/frequency/cf_axi_dds.ko
CC drivers/iio/frequency/cf_axi_dds_buffer_stream.mod.o
LD [M] drivers/iio/frequency/cf_axi_dds_buffer_stream.ko
CC drivers/iio/gyro/adis16080.mod.o
LD [M] drivers/iio/gyro/adis16080.ko
CC drivers/iio/gyro/adis16130.mod.o
LD [M] drivers/iio/gyro/adis16130.ko
CC drivers/iio/gyro/adis16136.mod.o
LD [M] drivers/iio/gyro/adis16136.ko
CC drivers/iio/gyro/adis16260.mod.o
LD [M] drivers/iio/gyro/adis16260.ko
CC drivers/iio/gyro/adxrs450.mod.o
LD [M] drivers/iio/gyro/adxrs450.ko
CC drivers/iio/imu/adis16400.mod.o
LD [M] drivers/iio/imu/adis16400.ko
CC drivers/iio/imu/adis16480.mod.o
LD [M] drivers/iio/imu/adis16480.ko
michael@mhenneri-D04:~/devel/hdl/github-linux-build/linux$