dt-bindings: gpio: renesas, rcar-gpio: Add r8a7742 (RZ/G1H) support

dt-bindings: gpio: renesas, rcar-gpio: Add r8a7742 (RZ/G1H) support

Renesas RZ/G1H (R8A7742) SoC GPIO blocks are identical to the R-Car Gen2
family. Add support for its GPIO controllers.

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: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>