ses: add enclosure logical id

Export the NAA logical id for the enclosure.  This is optionally
available from the sas_transport_class, but it is really a property of
the enclosure.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jens Axboe <axboe@fb.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>