MIPS: jz4780: DTS: Add nodes for ingenic pinctrl and gpio drivers

For a description of the devicetree node, please read
Documentation/devicetree/bindings/pinctrl/ingenic,pinctrl.txt

For a description of the gpio devicetree nodes, please read
Documentation/devicetree/bindings/gpio/ingenic,gpio.txt

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>