Device-Tree bindings for hdmiphy driver

Required properties:
- compatible: value should be one of the following:
	1) "samsung,exynos5-hdmiphy" <DEPRECATED>
	2) "samsung,exynos4210-hdmiphy".
	3) "samsung,exynos4212-hdmiphy".
- reg: Physical address of the hdmiphy device.
- phy-power-control: this child node represents phy power control
	register which is inside the pmu block (power management unit).

Example:

	hdmiphy {
		compatible = "samsung,exynos4210-hdmiphy";
		reg = <0x38>;

		phy-power-control {
			reg = <0x10040700 0x04>;
		};
	};