dt-bindings: arm: amlogic: add Amlogic A311D2 bindings

Add bindings for the Khadas Vim4 board, using A311D2 Soc from Amlogic T7
family chip.
Signed-off-by: Lucas Tanure <tanure@linux.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230629073419.207886-2-tanure@linux.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>

Documentation/devicetree/bindings/arm/amlogic.yaml

@@ -218,6 +218,13 @@ properties:
               - amlogic,aq222
           - const: amlogic,s4
 
+      - description: Boards with the Amlogic T7 A311D2 SoC
+        items:
+          - enum:
+              - khadas,vim4
+          - const: amlogic,a311d2
+          - const: amlogic,t7
+
 additionalProperties: true
 
 ...