Device Tree bindings for Freescale DCU DRM Driver

Required properties:
- compatible:		Should be one of
	* "fsl,ls1021a-dcu".
	* "fsl,vf610-dcu".

- reg:			Address and length of the register set for dcu.
- clocks:		From common clock binding: handle to dcu clock.
- clock-names:		From common clock binding: Shall be "dcu".
- big-endian		Boolean property, LS1021A DCU registers are big-endian.
- fsl,panel:		The phandle to panel node.

Examples:
dcu: dcu@2ce0000 {
	compatible = "fsl,ls1021a-dcu";
	reg = <0x0 0x2ce0000 0x0 0x10000>;
	clocks = <&platform_clk 0>;
	clock-names = "dcu";
	big-endian;
	fsl,panel = <&panel>;
};