Device-Tree bindings for hix5hd2 ir IP

Required properties:
	- compatible: Should contain "hisilicon,hix5hd2-ir", or:
		- "hisilicon,hi3796cv300-ir" for Hi3796CV300 IR device.
	- reg: Base physical address of the controller and length of memory
	  mapped region.
	- interrupts: interrupt-specifier for the sole interrupt generated by
	  the device. The interrupt specifier format depends on the interrupt
	  controller parent.
	- clocks: clock phandle and specifier pair.

Optional properties:
	- linux,rc-map-name: see rc.txt file in the same directory.
	- hisilicon,power-syscon: DEPRECATED. Don't use this in new dts files.
		Provide correct clocks instead.

Example node:

	ir: ir@f8001000 {
		compatible = "hisilicon,hix5hd2-ir";
		reg = <0xf8001000 0x1000>;
		interrupts = <0 47 4>;
		clocks = <&clock HIX5HD2_IR_CLOCK>;
		linux,rc-map-name = "rc-tivo";
	};