OMAP SoC DES crypto Module

Required properties:

- compatible : Should contain "ti,omap4-des"
- ti,hwmods: Name of the hwmod associated with the DES module
- reg : Offset and length of the register set for the module
- interrupts : the interrupt-specifier for the DES module
- clocks : A phandle to the functional clock node of the DES module
           corresponding to each entry in clock-names
- clock-names : Name of the functional clock, should be "fck"

Optional properties:
- dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
	Documentation/devicetree/bindings/dma/dma.txt
	Each entry corresponds to an entry in dma-names
- dma-names: DMA request names should include "tx" and "rx" if present

Example:
	/* DRA7xx SoC */
	des: des@480a5000 {
		compatible = "ti,omap4-des";
		ti,hwmods = "des";
		reg = <0x480a5000 0xa0>;
		interrupts = <GIC_SPI 82 IRQ_TYPE_LEVEL_HIGH>;
		dmas = <&sdma 117>, <&sdma 116>;
		dma-names = "tx", "rx";
		clocks = <&l3_iclk_div>;
		clock-names = "fck";
	};
