dt-bindings: iio: ad9467: add entries for for AD9434 & AD9265 ADCs

Add entries for the AD9434 & AD9265 high-speed ADCs which are supported by
the 'ad9467' driver.
Better describe the family of ADCs similar to AD9467 in the description.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200924080518.96410-5-alexandru.ardelean@analog.com

Documentation/devicetree/bindings/iio/adc/adi,ad9467.yaml

@@ -4,21 +4,30 @@
 $id: http://devicetree.org/schemas/iio/adc/adi,ad9467.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Analog Devices AD9467 High-Speed ADC
+title: Analog Devices AD9467 and similar High-Speed ADCs
 
 maintainers:
   - Michael Hennerich <michael.hennerich@analog.com>
   - Alexandru Ardelean <alexandru.ardelean@analog.com>
 
 description: |
-  The AD9467 is a 16-bit, monolithic, IF sampling analog-to-digital
-  converter (ADC).
+  The AD9467 and the parts similar with it, are high-speed analog-to-digital
+  converters (ADCs), operating in the range of 100 to 500 mega samples
+  per second (MSPS). Some parts support higher MSPS and some
+  lower MSPS, suitable for the intended application of each part.
 
+  All the parts support the register map described by Application Note AN-877
+   https://www.analog.com/media/en/technical-documentation/application-notes/AN-877.pdf
+
+  https://www.analog.com/media/en/technical-documentation/data-sheets/AD9265.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/AD9434.pdf
   https://www.analog.com/media/en/technical-documentation/data-sheets/AD9467.pdf
 
 properties:
   compatible:
     enum:
+      - adi,ad9265
+      - adi,ad9434
       - adi,ad9467
 
   reg: