mtd: nand: davinci: move bindings under mtd

Move bindings under mtd. Do this in order to make davinci-nand
driver usable by keystone architecture.

Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Taras Kondratiuk <taras@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Documentation/devicetree/bindings/mtd/davinci-nand.txt

@@ -0,0 +1,46 @@
+* Texas Instruments Davinci NAND
+
+This file provides information, what the device node for the
+davinci nand interface contain.
+
+Required properties:
+- compatible: "ti,davinci-nand";
+- reg : contain 2 offset/length values:
+        - offset and length for the access window
+        - offset and length for accessing the aemif control registers
+- ti,davinci-chipselect: Indicates on the davinci_nand driver which
+                         chipselect is used for accessing the nand.
+
+Recommended properties :
+- ti,davinci-mask-ale: mask for ale
+- ti,davinci-mask-cle: mask for cle
+- ti,davinci-mask-chipsel: mask for chipselect
+- ti,davinci-ecc-mode: ECC mode valid values for davinci driver:
+		- "none"
+		- "soft"
+		- "hw"
+- ti,davinci-ecc-bits: used ECC bits, currently supported 1 or 4.
+- ti,davinci-nand-buswidth: buswidth 8 or 16
+- ti,davinci-nand-use-bbt: use flash based bad block table support.
+
+nand device bindings may contain additional sub-nodes describing
+partitions of the address space. See partition.txt for more detail.
+
+Example(da850 EVM ):
+nand_cs3@62000000 {
+	compatible = "ti,davinci-nand";
+	reg = <0x62000000 0x807ff
+		0x68000000 0x8000>;
+	ti,davinci-chipselect = <1>;
+	ti,davinci-mask-ale = <0>;
+	ti,davinci-mask-cle = <0>;
+	ti,davinci-mask-chipsel = <0>;
+	ti,davinci-ecc-mode = "hw";
+	ti,davinci-ecc-bits = <4>;
+	ti,davinci-nand-use-bbt;
+
+	partition@180000 {
+		label = "ubifs";
+		reg = <0x180000 0x7e80000>;
+	};
+};