libcam: Include nvme opcode and status code routines from nvme_util.c

libcam in userspace also includes nvme_all.c which now depends on
nvme_util.c, so add nvme_util.c to libcam's sources. This requires
exporting the opcode and status code routines in nvme_util.c to
userspace as well as the kernel. In turn, this means nvmecontrol now
depends on libsbuf (which is already present in /lib).

Reported by: viswhin, Jenkins
Fixes: 60159a98a837 ("nvme: Move opcode and status code tables from base CAM to nvme_util.c")
Sponsored by: Chelsio Communications