pinctrl: mediatek: common: drop the wrappers around pinctrl_gpio_direction_input()

pinctrl_gpio_direction_input() now has the same signature as the
wrappers around it so we can drop them.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>