Add the new binding document for pinctrl on MediaTek mt8189.
Signed-off-by: Cathy Xu <ot_cathy.xu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/20250711094513.17073-2-ot_cathy.xu@mediatek.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
