dt-bindings: pinctrl: Add bindings for Actions Semi S700 SoC

Add pinctrl and pio bindings for Actions Semi S700 SoC.

Signed-off-by: Parthiban Nallathambi <pn@denx.de>
Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>