dt-bindings: i2c: renesas, iic: Document r8a7742 support

Document IIC controller for RZ/G1H (R8A7742) SoC, which is compatible
with R-Car Gen2 SoC family.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/i2c/renesas,iic.txt

@@ -4,6 +4,7 @@ Required properties:
 - compatible      :
 			- "renesas,iic-r8a73a4" (R-Mobile APE6)
 			- "renesas,iic-r8a7740" (R-Mobile A1)
+			- "renesas,iic-r8a7742" (RZ/G1H)
 			- "renesas,iic-r8a7743" (RZ/G1M)
 			- "renesas,iic-r8a7744" (RZ/G1N)
 			- "renesas,iic-r8a7745" (RZ/G1E)