scsi: Add PM_EVENT_POWEROFF into suspend callbacks

If the PM core uses hibernation callbacks for powering off the
system, drivers will receive PM_EVENT_POWEROFF and should handle
it the same as they previously handled PM_EVENT_HIBERNATE.

Support this case in the scsi driver.  No functional changes.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Link: https://patch.msgid.link/20251112224025.2051702-3-superm1@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: superm1

drivers/scsi/mesh.c

@@ -1762,6 +1762,7 @@ static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
 	case PM_EVENT_SUSPEND:
 	case PM_EVENT_HIBERNATE:
 	case PM_EVENT_FREEZE:
+	case PM_EVENT_POWEROFF:
 		break;
 	default:
 		return 0;

drivers/scsi/stex.c

@@ -1965,6 +1965,7 @@ static int stex_choice_sleep_mic(struct st_hba *hba, pm_message_t state)
 	case PM_EVENT_SUSPEND:
 		return ST_S3;
 	case PM_EVENT_HIBERNATE:
+	case PM_EVENT_POWEROFF:
 		hba->msi_lock = 0;
 		return ST_S4;
 	default: