dt-bindings: pinctrl: rockchip: add rk3308 SoC support

Add rk3308 SoC support to rockchip pinctrl.

Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
Link: https://lore.kernel.org/r/20191015091708.7934-2-jay.xu@rock-chips.com


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