pinctrl: rockchip: add rk3308 SoC support

This patch do support pinctrl for RK3308 SoCs.

Reviewed-by: Heiko Stuebner <[email protected]>
Signed-off-by: Jianqun Xu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>

Author: jayxurockchip