scsi: fnic: Add support to handle port channel RSCN

scsi: fnic: Add support to handle port channel RSCN

Add support to handle port channel RSCN.

Port channel RSCN is a Cisco vendor specific RSCN event. It is applicable
only to Cisco UCS fabrics.  If there's a change in the port channel
configuration, an RCSN is sent to fnic. This is used to serially reset the
scsi initiator fnics so that there's no all paths down scenario. The
affected fnics are added to a list that are reset with a small time gap
between them.

Reviewed-by: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Arulprabhu Ponnusamy <arulponn@cisco.com>
Reviewed-by: Gian Carlo Boffa <gcboffa@cisco.com>
Signed-off-by: Karan Tilak Kumar <kartilak@cisco.com>
Link: https://lore.kernel.org/r/20241212020312.4786-15-kartilak@cisco.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>