drivers/iio/adc/cf_axi_jesd204b: Misc changes

Add support for up to 8 Lanes
Add support for different GTX Rates and CDR data widths

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
iio/frequency/adf4350: Cleanup and Documentation

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>