Allwinner sunxi-sid

Required properties:
- compatible: "allwinner,sun4i-a10-sid" or "allwinner,sun7i-a20-sid"
- reg: Should contain registers location and length

= Data cells =
Are child nodes of qfprom, bindings of which as described in
bindings/nvmem/nvmem.txt

Example for sun4i:
	sid@01c23800 {
		compatible = "allwinner,sun4i-a10-sid";
		reg = <0x01c23800 0x10>
	};

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