dt-bindings: iio: dac: Generalize DAC common properties

Introduce a generalized DAC binding that can be used by DACs that have
similar properties adding output-range-microamp and output-range-microvolt.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
Link: https://patch.msgid.link/20240718051834.32270-4-kimseer.paller@analog.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>