Allwinner sunxi-sid

Required properties:
- compatible: "allwinner,sun4i-sid" or "allwinner,sun7i-a20-sid".
- reg: Should contain registers location and length

Example for sun4i:
	sid@01c23800 {
		compatible = "allwinner,sun4i-sid";
		reg = <0x01c23800 0x10>
	};

Example for sun7i:
	sid@01c23800 {
		compatible = "allwinner,sun7i-a20-sid";
		reg = <0x01c23800 0x200>
	};