iio:ad7476: Add ad7940 support

The AD7940 is a single channel 14 bit ADC similar to the ADCs already supported
by the ad7476 driver, but it does have a different shift factor.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2 files changed