dt-bindings: iio: adc: adi,ad7606: comment and sort the compatible names

AD7606-8 is referred to as AD7606 by Analog Devices. This comment aims
to avoid confusion. Also the compatible names were not sorted by
alphabetical order.
Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20240628-cleanup-ad7606-v2-2-96e02f90256d@baylibre.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml

@@ -20,9 +20,9 @@ properties:
   compatible:
     enum:
       - adi,ad7605-4
-      - adi,ad7606-8
-      - adi,ad7606-6
       - adi,ad7606-4
+      - adi,ad7606-6
+      - adi,ad7606-8  # Referred to as AD7606 (without -8) in the datasheet
       - adi,ad7606b
       - adi,ad7616