* Samsung Exynos Power Domains

Exynos processors include support for multiple power domains which are used
to gate power to one or more peripherals on the processor.

Required Properties:
- compatible: should be one of the following.
    * samsung,exynos4210-pd - for exynos4210 type power domain.
- reg: physical base address of the controller and length of memory mapped
    region.

Optional Properties:
- clocks: List of clock handles. The parent clocks of the input clocks to the
	devices in this power domain are set to oscclk before power gating
	and restored back after powering on a domain. This is required for
	all domains which are powered on and off and not required for unused
	domains.
- clock-names: The following clocks can be specified:
	- oscclk: Oscillator clock.
	- pclkN, clkN: Pairs of parent of input clock and input clock to the
		devices in this power domain. Maximum of 4 pairs (N = 0 to 3)
		are supported currently.

Node of a device using power domains must have a samsung,power-domain property
defined with a phandle to respective power domain.

Example:

	lcd0: power-domain-lcd0 {
		compatible = "samsung,exynos4210-pd";
		reg = <0x10023C00 0x10>;
	};

	mfc_pd: power-domain@10044060 {
		compatible = "samsung,exynos4210-pd";
		reg = <0x10044060 0x20>;
		clocks = <&clock CLK_FIN_PLL>, <&clock CLK_MOUT_SW_ACLK333>,
			<&clock CLK_MOUT_USER_ACLK333>;
		clock-names = "oscclk", "pclk0", "clk0";
	};

Example of the node using power domain:

	node {
		/* ... */
		samsung,power-domain = <&lcd0>;
		/* ... */
	};
