Binding for Texas Instruments clockdomain.

This binding uses the common clock binding[1]. Every clock on
TI SoC belongs to one clockdomain, but software only needs this
information for specific clocks which require their parent
clockdomain to be controlled when the clock is enabled/disabled.

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

Required properties:
- compatible : shall be "ti,clockdomain"
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : link phandles of clocks within this domain

Examples:
	dss_clkdm: dss_clkdm {
		compatible = "ti,clockdomain";
		clocks = <&dss1_alwon_fck_3430es2>, <&dss_ick_3430es2>;
	};
