arm64: dts: actions: s900: Add gpio properties to pinctrl node

Add gpio properties to pinctrl node for Actions Semi S900 SoC.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>