[SCSI] mpt2sas: fix crash due to Watchdog is active while OS in standby mode

Fix oops ocurring at hibernation time.  This oops was due to the firmware fault
watchdog timer still running after we freed resources. To fix the issue we need
to terminate the watchdog timer at hibernation time.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>