dt-bindings: arm: imx: Add the i.MX8MP EVK board

Add board binding for i.MX8MP EVK board.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -324,6 +324,12 @@ properties:
               - fsl,imx8mn-evk            # i.MX8MN LPDDR4 EVK Board
           - const: fsl,imx8mn
 
+      - description: i.MX8MP based Boards
+        items:
+          - enum:
+              - fsl,imx8mp-evk            # i.MX8MP EVK Board
+          - const: fsl,imx8mp
+
       - description: i.MX8MQ based Boards
         items:
           - enum: