pinctrl: mediatek: Add EINT support to MTK pinctrl driver.

MTK SoC support external interrupt(EINT) from most SoC pins.
Add EINT support to pinctrl driver.

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

diff --cc drivers/pinctrl/mediatek/pinctrl-mt8135.c
Simple merge

diff --cc drivers/pinctrl/mediatek/pinctrl-mtk-common.c
Simple merge

diff --cc drivers/pinctrl/mediatek/pinctrl-mtk-common.h
Simple merge