Device-Tree bindings for SUNXI IR controller found in sunXi SoC family

Required properties:
- compatible	    : "allwinner,sun4i-a10-ir" or "allwinner,sun5i-a13-ir"
- clocks	    : list of clock specifiers, corresponding to
		      entries in clock-names property;
- clock-names	    : should contain "apb" and "ir" entries;
- interrupts	    : should contain IR IRQ number;
- reg		    : should contain IO map address for IR.

Optional properties:
- linux,rc-map-name: see rc.txt file in the same directory.
- resets : phandle + reset specifier pair
- clock-frequency  : IR Receiver clock frequency, in Hertz. Defaults to 8 MHz
		     if missing.

Example:

ir0: ir@1c21800 {
	compatible = "allwinner,sun4i-a10-ir";
	clocks = <&apb0_gates 6>, <&ir0_clk>;
	clock-names = "apb", "ir";
	clock-frequency = <3000000>;
	resets = <&apb0_rst 1>;
	interrupts = <0 5 1>;
	reg = <0x01C21800 0x40>;
	linux,rc-map-name = "rc-rc6-mce";
};