scsi: mpi3mr: Enable Enclosure device add event

Enable and process the Enclosure device add event.

Link: https://lore.kernel.org/r/20220804131226.16653-5-sreekanth.reddy@broadcom.com


Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>