dt-bindings: Add max12xx SPI ADC series as trivial devices

Update the compatible list with three Maxim ADCs compatibles.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
1 file changed