dt/bindings: qcom_nandc: Add DT bindings

* Qualcomm NAND controller

Required properties:

- compatible:		should be "qcom,ipq806x-nand"

- reg:			MMIO address range

- clocks:		must contain core clock and always on clock

- clock-names:		must contain "core" for the core clock and "aon" for the

			always on clock

- dmas:			DMA specifier, consisting of a phandle to the ADM DMA

			controller node and the channel number to be used for

			NAND. Refer to dma.txt and qcom_adm.txt for more details

- dma-names:		must be "rxtx"

- qcom,cmd-crci:	must contain the ADM command type CRCI block instance

			number specified for the NAND controller on the given

			platform

- qcom,data-crci:	must contain the ADM data type CRCI block instance

			number specified for the NAND controller on the given

			platform

- #address-cells:	<1> - subnodes give the chip-select number

- #size-cells:		<0>

* NAND chip-select

Each controller may contain one or more subnodes to represent enabled

chip-selects which (may) contain NAND flash chips. Their properties are as

follows.

Required properties:

- compatible:		should contain "qcom,nandcs"

- reg:			a single integer representing the chip-select

			number (e.g., 0, 1, 2, etc.)

- #address-cells:	see partition.txt

- #size-cells:		see partition.txt

- nand-ecc-strength:	see nand.txt

- nand-ecc-step-size:	must be 512. see nand.txt for more details.

Optional properties:

- nand-bus-width:	see nand.txt

Each nandcs device node may optionally contain a 'partitions' sub-node, which

further contains sub-nodes describing the flash partition mapping. See

partition.txt for more detail.

Example:

nand@1ac00000 {

	compatible = "qcom,ebi2-nandc";

	reg = <0x1ac00000 0x800>;

	clocks = <&gcc EBI2_CLK>,

		 <&gcc EBI2_AON_CLK>;

	clock-names = "core", "aon";

	dmas = <&adm_dma 3>;

	dma-names = "rxtx";

	qcom,cmd-crci = <15>;

	qcom,data-crci = <3>;

	#address-cells = <1>;

	#size-cells = <0>;

	nandcs@0 {

		compatible = "qcom,nandcs";

		reg = <0>;

		nand-ecc-strength = <4>;

		nand-ecc-step-size = <512>;

		nand-bus-width = <8>;

		partitions {

			compatible = "fixed-partitions";

			#address-cells = <1>;

			#size-cells = <1>;

			partition@0 {

				label = "boot-nand";

				reg = <0 0x58a0000>;

			};

			partition@58a0000 {

				label = "fs-nand";

				reg = <0x58a0000 0x4000000>;

			};

		};

	};

};