dt-bindings: iio: adc: Document Renesas RZ/G2UL ADC

Document Renesas RZ/G2UL ADC bindings. RZ/G2UL ADC is almost identical
to RZ/G2L, but it has 2 analog input channels compared to 8 channels
on the RZ/G2L.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220515060337.16513-2-biju.das.jz@bp.renesas.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/renesas,rzg2l-adc.yaml

@@ -19,6 +19,7 @@ properties:
   compatible:
     items:
       - enum:
+          - renesas,r9a07g043-adc   # RZ/G2UL
           - renesas,r9a07g044-adc   # RZ/G2L
           - renesas,r9a07g054-adc   # RZ/V2L
       - const: renesas,rzg2l-adc
@@ -76,16 +77,35 @@ patternProperties:
     properties:
       reg:
         description: |
-          The channel number. It can have up to 8 channels numbered from 0 to 7.
-        items:
-          - minimum: 0
-            maximum: 7
+          The channel number.
 
     required:
       - reg
 
     additionalProperties: false
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,r9a07g043-adc
+    then:
+      patternProperties:
+        "^channel@[2-7]$": false
+        "^channel@[0-1]$":
+          properties:
+            reg:
+              minimum: 0
+              maximum: 1
+    else:
+      patternProperties:
+        "^channel@[0-7]$":
+          properties:
+            reg:
+              minimum: 0
+              maximum: 7
+
 additionalProperties: false
 
 examples: