Amlogic NAND Flash Controller (NFC) for GXBB/GXL/AXG family SoCs

This file documents the properties in addition to those available in
the MTD NAND bindings.

Required properties:
- compatible : contains one of:
  - "amlogic,meson-gxl-nfc"
  - "amlogic,meson-axg-nfc"
- clocks     :
	A list of phandle + clock-specifier pairs for the clocks listed
	in clock-names.

- clock-names: Should contain the following:
	"core" - NFC module gate clock
	"device" - device clock from eMMC sub clock controller
	"rx" - rx clock phase
	"tx" - tx clock phase

- amlogic,mmc-syscon	: Required for NAND clocks, it's shared with SD/eMMC
				controller port C

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

Other properties:
see Documentation/devicetree/bindings/mtd/nand-controller.yaml for generic bindings.

Example demonstrate on AXG SoC:

	sd_emmc_c_clkc: mmc@7000 {
		compatible = "amlogic,meson-axg-mmc-clkc", "syscon";
		reg = <0x0 0x7000 0x0 0x800>;
	};

	nand-controller@7800 {
		compatible = "amlogic,meson-axg-nfc";
		reg = <0x0 0x7800 0x0 0x100>;
		#address-cells = <1>;
		#size-cells = <0>;
		interrupts = <GIC_SPI 34 IRQ_TYPE_EDGE_RISING>;

		clocks = <&clkc CLKID_SD_EMMC_C>,
			<&sd_emmc_c_clkc CLKID_MMC_DIV>,
			<&sd_emmc_c_clkc CLKID_MMC_PHASE_RX>,
			<&sd_emmc_c_clkc CLKID_MMC_PHASE_TX>;
		clock-names = "core", "device", "rx", "tx";
		amlogic,mmc-syscon = <&sd_emmc_c_clkc>;

		pinctrl-names = "default";
		pinctrl-0 = <&nand_pins>;

		nand@0 {
			reg = <0>;
			#address-cells = <1>;
			#size-cells = <1>;

			nand-on-flash-bbt;
		};
	};