nvmem: Add DT binding documentation for Vybrid OCOTP driver

Add the devicetree bindings for the Freescale Vybrid On-Chip
OTP driver.
Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/nvmem/vf610-ocotp.txt

+On-Chip OTP Memory for Freescale Vybrid
+
+Required Properties:
+  compatible:
+  - "fsl,vf610-ocotp" for VF5xx/VF6xx
+  #address-cells : Should be 1
+  #size-cells : Should be 1
+  reg : Address and length of OTP controller and fuse map registers
+  clocks : ipg clock we associate with the OCOTP peripheral
+
+Example for Vybrid VF5xx/VF6xx:
+
+	ocotp: ocotp@400a5000 {
+		compatible = "fsl,vf610-ocotp";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		reg = <0x400a5000 0xCF0>;
+		clocks = <&clks VF610_CLK_OCOTP>;
+	};