crypto: rockchip - add DT bindings documentation

Rockchip Electronics And Security Accelerator

Required properties:

- compatible: Should be "rockchip,rk3288-crypto"

- reg: Base physical address of the engine and length of memory mapped

       region

- interrupts: Interrupt number

- clocks: Reference to the clocks about crypto

- clock-names: "aclk" used to clock data

	       "hclk" used to clock data

	       "sclk" used to clock crypto accelerator

	       "apb_pclk" used to clock dma

- resets: Must contain an entry for each entry in reset-names.

	  See ../reset/reset.txt for details.

- reset-names: Must include the name "crypto-rst".

Examples:

	crypto: cypto-controller@ff8a0000 {

		compatible = "rockchip,rk3288-crypto";

		reg = <0xff8a0000 0x4000>;

		interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;

		clocks = <&cru ACLK_CRYPTO>, <&cru HCLK_CRYPTO>,

			 <&cru SCLK_CRYPTO>, <&cru ACLK_DMAC1>;

		clock-names = "aclk", "hclk", "sclk", "apb_pclk";

		resets = <&cru SRST_CRYPTO>;

		reset-names = "crypto-rst";

		status = "okay";

	};