Xilinx Zynq GPIO controller Device Tree Bindings
-------------------------------------------

Required properties:
- #gpio-cells 		: Should be two
			  - First cell is the GPIO line number
			  - Second cell is used to specify optional
			    parameters (unused)
- compatible		: Should be "xlnx,zynq-gpio-1.0"
- clocks		: Clock specifier (see clock bindings for details)
- gpio-controller	: Marks the device node as a GPIO controller.
- interrupts		: Interrupt specifier (see interrupt bindings for
			  details)
- interrupt-parent	: Must be core interrupt controller
- reg			: Address and length of the register set for the device

Example:
	gpio@e000a000 {
		#gpio-cells = <2>;
		compatible = "xlnx,zynq-gpio-1.0";
		clocks = <&clkc 42>;
		gpio-controller;
		interrupt-parent = <&intc>;
		interrupts = <0 20 4>;
		reg = <0xe000a000 0x1000>;
	};

Add Zynq GPIO devicetree bindings documentation
devicetree: Add Zynq GPIO devicetree bindings documentation

Add gpio-zynq bindings documentation.

Signed-off-by: Harini Katakam <460912b7442082efd17dd2415499351621819deb@xilinx.com>
Signed-off-by: Soren Brinkmann <f9793267bd24439886cd4a142f9642a9bcc6364b@xilinx.com>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>
