Documentation: crypto: Add DT binding info for the img hw hash accelerator

Imagination Technologies hardware hash accelerator

The hash accelerator provides hardware hashing acceleration for

SHA1, SHA224, SHA256 and MD5 hashes

Required properties:

- compatible : "img,hash-accelerator"

- reg : Offset and length of the register set for the module, and the DMA port

- interrupts : The designated IRQ line for the hashing module.

- dmas : DMA specifier as per Documentation/devicetree/bindings/dma/dma.txt

- dma-names : Should be "tx"

- clocks : Clock specifiers

- clock-names : "sys" Used to clock the hash block registers

		"hash" Used to clock data through the accelerator

Example:

	hash: hash@18149600 {

	compatible = "img,hash-accelerator";

		reg = <0x18149600 0x100>, <0x18101100 0x4>;

		interrupts = <GIC_SHARED 59 IRQ_TYPE_LEVEL_HIGH>;

		dmas = <&dma 8 0xffffffff 0>;

		dma-names = "tx";

		clocks = <&cr_periph SYS_CLK_HASH>, <&clk_periph PERIPH_CLK_ROM>;

		clock-names = "sys", "hash";

	};