scsi: ufs: Flush exception event before suspend

Exception event can be raised by the device when system suspend is in
progress. This will result in unclocked register access in exception event
handler as clocks will be turned off during suspend. This change makes sure
to flush exception event handler work in suspend before disabling clocks to
avoid unclocked register access issue.

Link: https://lore.kernel.org/r/1581392451-28743-2-git-send-email-cang@codeaurora.org


Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>