ARM: shmobile: Document R-Car V3M SoC DT bindings

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/arm/shmobile.txt

@@ -39,6 +39,8 @@ SoCs:
     compatible = "renesas,r8a7795"
   - R-Car M3-W (R8A77960)
     compatible = "renesas,r8a7796"
+  - R-Car V3M (R8A77970)
+    compatible = "renesas,r8a77970"
   - R-Car D3 (R8A77995)
     compatible = "renesas,r8a77995"