dt-bindings: pinctrl: renesas,rzg2l-pinctrl: Allow 'input' and 'output-enable' properties

On the RZ/G3S SMARC platform, the 'input' property is utilized in
gpio-hog nodes, and the 'output-enable' property is used for ETH0/1 TXC
pins.  Update the binding documentation to include these properties,
addressing the following dtbs_check warnings:

    arch/arm64/boot/dts/renesas/r9a08g045s33-smarc.dtb: pinctrl@11030000: key-1-gpio-hog: 'anyOf' conditional failed, one must be fixed:
	    'input' does not match any of the regexes: 'pinctrl-[0-9]+'

    arch/arm64/boot/dts/renesas/r9a08g045s33-smarc.dtb: pinctrl@11030000: eth0: 'anyOf' conditional failed, one must be fixed:
	    'output-enable' does not match any of the regexes: 'pinctrl-[0-9]+'

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240313083828.5048-1-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>