dt-bindings: altera: Add Chameleon v3 board

Add Mercury+ AA1 boards category, together with the Chameleon v3 board.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Paweł Anikiel <pan@semihalf.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

Documentation/devicetree/bindings/arm/altera.yaml

@@ -25,7 +25,14 @@ properties:
         items:
           - enum:
               - altr,socfpga-arria10-socdk
-              - enclustra,mercury-aa1
+          - const: altr,socfpga-arria10
+          - const: altr,socfpga
+
+      - description: Mercury+ AA1 boards
+        items:
+          - enum:
+              - google,chameleon-v3
+          - const: enclustra,mercury-aa1
           - const: altr,socfpga-arria10
           - const: altr,socfpga