arm64: mediatek: Add Pinctrl/GPIO/EINT driver for mt8173.

Add mt8173 support using mediatek common pinctrl driver.
MT8173 have a different ies_smt setting register than mt8135,
so adding this support to common code.

Signed-off-by: Hongzhou Yang <hongzhou.yang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>