rockchip: defconfig: Clean the unused pinctrl config

If we used the pinctrl-rockchip driver, these config is not needed,
so remove them.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>