scsi: ufs: Track system suspend / resume activity

scsi: ufs: Track system suspend / resume activity

Add a new boolean variable that tracks whether the system is suspending,
suspended or resuming. This information will be used in a later commit to
fix a deadlock between the SCSI error handler and the suspend code.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221018202958.1902564-9-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>