NVMe controllers implement different versions of the spec,
and different features of it. It is useful to gather this
information when debugging.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210127212137.3482291-3-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>