dt-bindings: power: rcar-sysc: Document r8a774c0 sysc

Document bindings for the RZ/G2E (a.k.a. R8A774C0) system
controller.
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/power/renesas,rcar-sysc.txt

@@ -11,6 +11,7 @@ Required properties:
       - "renesas,r8a7745-sysc" (RZ/G1E)
       - "renesas,r8a77470-sysc" (RZ/G1C)
       - "renesas,r8a774a1-sysc" (RZ/G2M)
+      - "renesas,r8a774c0-sysc" (RZ/G2E)
       - "renesas,r8a7779-sysc" (R-Car H1)
       - "renesas,r8a7790-sysc" (R-Car H2)
       - "renesas,r8a7791-sysc" (R-Car M2-W)