crypto: brcm - DT documentation for Broadcom SPU hardware

The Broadcom Secure Processing Unit (SPU) hardware supports symmetric

cryptographic offload for Broadcom SoCs. A SoC may have multiple SPU hardware

blocks.

Required properties:

- compatible: Should be one of the following:

  brcm,spum-crypto - for devices with SPU-M hardware

  brcm,spu2-crypto - for devices with SPU2 hardware

  brcm,spu2-v2-crypto - for devices with enhanced SPU2 hardware features like SHA3

  and Rabin Fingerprint support

  brcm,spum-nsp-crypto - for the Northstar Plus variant of the SPU-M hardware

- reg: Should contain SPU registers location and length.

- mboxes: The mailbox channel to be used to communicate with the SPU.

  Mailbox channels correspond to DMA rings on the device.

Example:

	crypto@612d0000 {

		compatible = "brcm,spum-crypto";

		reg = <0 0x612d0000 0 0x900>;

		mboxes = <&pdc0 0>;

	};