dt-bindings: arm: amlogic: Document the boards with the BPI-CM4 connected

The BPI-CM4 module with an Amlogic A311D SoC is a module compatible
with the Raspberry Pi CM4 specifications.

Document the boards using this module, by specifying the BananaPi CM4
compatible in addition to the baseboard compatible.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20230303-topic-amlogic-upstream-bpi-cm4-v2-1-2ecfde76fc4d@linaro.org
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

Author: superna9999

Documentation/devicetree/bindings/arm/amlogic.yaml

@@ -159,6 +159,14 @@ properties:
           - const: amlogic,a311d
           - const: amlogic,g12b
 
+      - description: Boards using the BPI-CM4 module with Amlogic Meson G12B A311D SoC
+        items:
+          - enum:
+              - bananapi,bpi-cm4io
+          - const: bananapi,bpi-cm4
+          - const: amlogic,a311d
+          - const: amlogic,g12b
+
       - description: Boards with the Amlogic Meson G12B S922X SoC
         items:
           - enum: