pinctrl/rockchip: support setting input-enable param

Handle the PIN_CONFIG_INPUT_ENABLE param for configuring GPIOs as input.

Signed-off-by: Caleb Connolly <kc@postmarketos.org>
Link: https://lore.kernel.org/r/20220328005005.72492-3-kc@postmarketos.org


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