iio: ad799x: Fix ad7991/ad7995/ad7999 config setup
iio: ad799x: Fix ad7991/ad7995/ad7999 config setup

The ad7991/ad7995/ad7999 does not have a configuration register like the
other devices that can be written and read. The configuration is written as
part of the conversion sequence.

Fixes: 0f7ddcc1bff1 ("iio:adc:ad799x: Write default config on probe and reset alert status on probe")
Signed-off-by: Lars-Peter Clausen <3318dc5ce3e4fb7c28a0b841b6801c884e1d0896@metafoo.de>
Tested-by: Mike Looijmans <a3a80a5bf09f2a16fb39154c4e7d0b2d849b0dfb@topic.nl>
Signed-off-by: Jonathan Cameron <09f65b71b7655725897b2fd41a09a0cefe2e1ace@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs