pinctrl: mediatek: fix direction control issue

Since input-enable/disable and input-schmitt-enable/disable are
workable when gpio direction is input, so add direction setting
when do input-enable/disable and input-schmitt-enable/disable
properties.

Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>