ARM: dts: Add RDA8810PL GPIO controllers

ARM: dts: Add RDA8810PL GPIO controllers

Add GPIO controllers for RDA8810PL SoC. There are 4 GPIO controllers
in this SoC with maximum of 32 gpios. Except GPIOC, all controllers
are capable of generating edge/level interrupts from first 8 lines.

Link: https://lore.kernel.org/r/20191030101154.6312-2-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>