Fix support for the stk3311 light/proximity sensor by supporting configuring GPIOs as input

This series extends the rockchip pinctrl/gpio drivers to handle configuring GPIOs as input via pinconf. It then adds a pinconf for the stk3311 interrupt.

The pinctrl and gpio drivers match the same DT node, so there's some "fun" deferred probe handling which was previously only used for configuring output GPIOs, that had to be made generic so that it could /also/ handle configuring GPIOs as inputs.

(this deprecates the u-boot hack: https://github.com/dreemurrs-embedded/Pine64-Arch/blob/master/PKGBUILDS/pine64/uboot-pinephonepro/reconfigure-GPIO4_D3-as-input-on-pinephone-pro.patch)

tl;dr, way harder than it had to be