Tegra Virtual Storage driver

Virtual Storage Driver is the front end driver that interfaces with the
Storage Virtualization System for Tegra SOC and provides a block device
interface

Required Properties:
- compatible: should be "nvidia,tegra-hv-storage"
- instance:   to identify a specific instance of the device
- ivc:        ivc channel to used for communication with Virtualization System
- mempool:    mempool used for data transfers with Virtualization System

Example:
	tegra_virt_storage0 {
		compatible = "nvidia,tegra-hv-storage";
		instance = <0>;
		ivc = <&tegra_hv 63>;
		mempool = <10>;
		status = "okay";
	};

