Allwinner NAND Flash Controller (NFC)

Required properties:
- compatible : "allwinner,sun4i-a10-nand".
- reg : shall contain registers location and length for data and reg.
- interrupts : shall define the nand controller interrupt.
- #address-cells: shall be set to 1. Encode the nand CS.
- #size-cells : shall be set to 0.
- clocks : shall reference nand controller clocks.
- clock-names : nand controller internal clock names. Shall contain :
    * "ahb" : AHB gating clock
    * "mod" : nand controller clock

Optional children nodes:
Children nodes represent the available nand chips.

Optional properties:
- allwinner,rb : shall contain the native Ready/Busy ids.
 or
- rb-gpios : shall contain the gpios used as R/B pins.
- nand-ecc-mode : one of the supported ECC modes ("hw", "hw_syndrome", "soft",
  "soft_bch" or "none")

see Documentation/devicetree/mtd/nand.txt for generic bindings.


Examples:
nfc: nand@01c03000 {
	compatible = "allwinner,sun4i-a10-nand";
	reg = <0x01c03000 0x1000>;
	interrupts = <0 37 1>;
	clocks = <&ahb_gates 13>, <&nand_clk>;
	clock-names = "ahb", "mod";
	#address-cells = <1>;
	#size-cells = <0>;
	pinctrl-names = "default";
	pinctrl-0 = <&nand_pins_a &nand_cs0_pins_a &nand_rb0_pins_a>;
	status = "okay";

	nand@0 {
		reg = <0>;
		allwinner,rb = <0>;
		nand-ecc-mode = "soft_bch";
	};
};
