dt-bindings: arm: document Renesas V3HSK board bindings

Document the V3H Starter Kit device tree bindings, listing it as
a supported board.

This allows to use checkpatch.pl to validate .dts files referring to
the V3HSK board.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/arm/shmobile.txt

@@ -130,6 +130,8 @@ Boards:
     compatible = "renesas,sk-rzg1m", "renesas,r8a7743"
   - Stout (ADAS Starterkit, Y-R-CAR-ADAS-SKH2-BOARD)
     compatible = "renesas,stout", "renesas,r8a7790"
+  - V3HSK (Y-ASK-RCAR-V3H-WS10)
+    compatible = "renesas,v3hsk", "renesas,r8a77980"
   - V3MSK (Y-ASK-RCAR-V3M-WS10)
     compatible = "renesas,v3msk", "renesas,r8a77970"
   - Wheat (RTP0RC7792ASKB0000JE)