NVMe: Add nvme-scsi.c

Translates SCSI commands in SG_IO ioctl to NVMe commands.
Uses the scsi-nvme translation spec from nvmexpress.org as reference.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

diff --cc drivers/block/Makefile
Simple merge

diff --cc drivers/block/nvme-core.c
Simple merge

diff --cc drivers/block/nvme-scsi.c
Simple merge

diff --cc include/linux/nvme.h
Simple merge