dt-bindings: soc: renesas: Document R-Car V4M-7 Gray Hawk Single

Document the compatible values for the Renesas R-Car V4M-7
(R8A779H2) SoC, as used on the Renesas Gray Hawk Single board.
R-Car V4M-7 is an updated version of R-Car V4M (R8A779H0).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: "Rob Herring (Arm)" <robh@kernel.org>
Link: https://lore.kernel.org/b4283a68aa01c82d4435ee8334093dcbdf5bd4d2.1750931027.git.geert+renesas@glider.be

Author: geertu

Documentation/devicetree/bindings/soc/renesas/renesas.yaml

@@ -388,6 +388,13 @@ properties:
               - renesas,gray-hawk-single # Gray Hawk Single board (RTP8A779H0ASKB0F10S)
           - const: renesas,r8a779h0
 
+      - description: R-Car V4M-7 (R8A779H2)
+        items:
+          - enum:
+              - renesas,gray-hawk-single # Gray Hawk Single board (RTP8A779H2ASKB0F10SA001)
+          - const: renesas,r8a779h2 # ES2.x
+          - const: renesas,r8a779h0
+
       - description: R-Car H3e (R8A779M0)
         items:
           - enum: