Binding for Texas Instruments autoidle clock.

This binding uses the common clock binding[1]. It assumes a register mapped
clock which can be put to idle automatically by hardware based on the usage
and a configuration bit setting. Autoidle clock is never an individual
clock, it is always a derivative of some basic clock like a gate, divider,
or fixed-factor.

[1] Documentation/devicetree/bindings/clock/clock-bindings.txt

Required properties:
- reg : offset for the register controlling the autoidle
- ti,autoidle-shift : bit shift of the autoidle enable bit
- ti,invert-autoidle-bit : autoidle is enabled by setting the bit to 0

Examples:
	dpll_core_m4_ck: dpll_core_m4_ck {
		#clock-cells = <0>;
		compatible = "ti,divider-clock";
		clocks = <&dpll_core_x2_ck>;
		ti,max-div = <31>;
		ti,autoidle-shift = <8>;
		reg = <0x2d38>;
		ti,index-starts-at-one;
		ti,invert-autoidle-bit;
	};

	dpll_usb_clkdcoldo_ck: dpll_usb_clkdcoldo_ck {
		#clock-cells = <0>;
		compatible = "ti,fixed-factor-clock";
		clocks = <&dpll_usb_ck>;
		ti,clock-div = <1>;
		ti,autoidle-shift = <8>;
		reg = <0x01b4>;
		ti,clock-mult = <1>;
		ti,invert-autoidle-bit;
	};
