pinctrl: mediatek: add mt8188 driver

Add pinctrl driver support for MediaTek SoC mt8188.

Signed-off-by: Hui.Liu <hui.liu@mediatek.com>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220818075012.20880-3-hui.liu@mediatek.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>