dt-bindings: freescale: Add bindings for the tigerp module

Add bindings for the tigerp module present on i.MX51.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/freescale/tigerp.txt

+* Freescale Tigerp platform module
+
+Required properties:
+- compatible : Should be "fsl,imx51-tigerp"
+- reg : Address and length of the register set for the device
+
+Example:
+
+tigerp: tigerp@83fa0000 {
+	compatible = "fsl,imx51-tigerp";
+	reg = <0x83fa0000 0x28>;
+};