Binding for Texas Instruments ADPLL clock.

This binding uses the common clock binding[1]. It assumes a
register-mapped ADPLL with two to three selectable input clocks
and three to four children.

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

Required properties:
- compatible : shall be one of "ti,dm814-adpll-s-clock" or
  "ti,dm814-adpll-lj-clock" depending on the type of the ADPLL
- #clock-cells : from common clock binding; shall be set to 1.
- clocks : link phandles of parent clocks clkinp and clkinpulow, note
  that the adpll-s-clock also has an optional clkinphif
- reg : address and length of the register set for controlling the ADPLL.

Examples:
	adpll_mpu_ck: adpll@40 {
		#clock-cells = <1>;
		compatible = "ti,dm814-adpll-s-clock";
		reg = <0x40 0x40>;
		clocks = <&devosc_ck &devosc_ck &devosc_ck>;
		clock-names = "clkinp", "clkinpulow", "clkinphif";
		clock-output-names = "481c5040.adpll.dcoclkldo",
				     "481c5040.adpll.clkout",
				     "481c5040.adpll.clkoutx2",
				     "481c5040.adpll.clkouthif";
	};

	adpll_dsp_ck: adpll@80 {
		#clock-cells = <1>;
		compatible = "ti,dm814-adpll-lj-clock";
		reg = <0x80 0x30>;
		clocks = <&devosc_ck &devosc_ck>;
		clock-names = "clkinp", "clkinpulow";
		clock-output-names = "481c5080.adpll.dcoclkldo",
				     "481c5080.adpll.clkout",
				     "481c5080.adpll.clkoutldo";
	};