ImgTec TZ1090 PDC GPIO Controller

Required properties:
- compatible: Compatible property value should be "img,tz1090-pdc-gpio".

- reg: Physical base address of the controller and length of memory mapped
  region. This starts at and cover the SOC_GPIO_CONTROL registers.

- gpio-controller: Specifies that the node is a gpio controller.

- #gpio-cells: Should be 2. The syntax of the gpio specifier used by client
  nodes should have the following values.
     <[phandle of the gpio controller node]
      [PDC gpio number]
      [gpio flags]>

  Values for gpio specifier:
  - GPIO number: a value in the range 0 to 6.
  - GPIO flags: bit field of flags, as defined in <dt-bindings/gpio/gpio.h>.
    Only the following flags are supported:
      GPIO_ACTIVE_HIGH
      GPIO_ACTIVE_LOW

Optional properties:
- gpio-ranges: Mapping to pin controller pins (as described in
  Documentation/devicetree/bindings/gpio/gpio.txt)

- interrupts: Individual syswake interrupts (other GPIOs cannot interrupt)


Example:

	pdc_gpios: gpio-controller@02006500 {
		gpio-controller;
		#gpio-cells = <2>;

		compatible = "img,tz1090-pdc-gpio";
		reg = <0x02006500 0x100>;

		interrupt-parent = <&pdc>;
		interrupts =	<8  IRQ_TYPE_NONE>,	/* Syswake 0 */
				<9  IRQ_TYPE_NONE>,	/* Syswake 1 */
				<10 IRQ_TYPE_NONE>;	/* Syswake 2 */
		gpio-ranges = <&pdc_pinctrl 0 0 7>;
	};
