scsi: megaraid_sas: Do not fire DCMDs during PCI shutdown/detach

scsi: megaraid_sas: Do not fire DCMDs during PCI shutdown/detach

Orabug: 25568930

This patch addresses the issue of driver firing DCMDs in PCI
shutdown/detach path irrespective of firmware state.  Driver will now
check whether firmware is in operational state or not before firing
DCMDs. If firmware is in unrecoverable state or does not become
operational within specfied time, driver will skip firing DCMDs.

[mkp: fixed typos]

Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit a1dfd62c1ebce71a62f5de002c694d5a22fb32a1)
Signed-off-by: Brian Maly <brian.maly@oracle.com>