Broadcom iProc Multi Host Bridge (MHB)

Certain Broadcom iProc SoCs have a multi host bridge (MHB) block that controls
the connection and configuration of 1) internal PCIe serdes; 2) PCIe endpoint
interface; 3) access to the Nitro (network processing) engine

This node allows access to these MHB registers via syscon.

Required properties:
- compatible: should contain:
		"brcm,sr-mhb", "syscon" for Stingray
- reg: base address and range of the MHB registers

Example:
	mhb: syscon@60401000 {
		compatible = "brcm,sr-mhb", "syscon";
		reg = <0 0x60401000 0 0x38c>;
	};