dt-bindings: arm: fsl: Add support for ZII i.MX7 RPU2 board

Add support for ZII i.MX7 RPU2 board.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -157,6 +157,7 @@ properties:
           - enum:
               - fsl,imx7d-sdb             # i.MX7 SabreSD Board
               - tq,imx7d-mba7             # i.MX7D TQ MBa7 with TQMa7D SoM
+              - zii,imx7d-rpu2            # ZII RPU2 Board
           - const: fsl,imx7d
 
       - description: