Rockchip NANDC Controller for SOC

Required properties:
- compatible : "rockchip,rk-nandc".
- reg : shall contain registers location and length for data and reg.
- interrupts : shall define the nandc controller interrupt.
- nandc_id : shall reference the number of nandc controllers;
- clocks : shall reference nandc controller clocks.
- clock-names : nandc controller internal clock names. Shall contain :
    * "clk_nandc" : nand controller clock
    * "hclk_nandc" : nandc ahb clock gate
    * "g_clk_nandc" : nandc enable clock gate

Examples:
nandc: nandc@30100000 {
	compatible = "rockchip,rk-nandc";
	reg = <0x0 0xff4b0000 0x0 0x4000>;
	interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
	nandc_id = <0>;
	clocks = <&clk_nandc>, <&clk_gates15 3>, <&clk_gates5 3>;
	clock-names = "clk_nandc", "hclk_nandc", "g_clk_nandc";
	status = "disabled";
};