scsi: scsi_debug: Avoid PI being disabled when TPGS is enabled

scsi: scsi_debug: Avoid PI being disabled when TPGS is enabled

It was not possible to enable both T10 PI and TPGS because they share
the same byte in the INQUIRY response. Logically OR the TPGS value
instead of using assignment.

Orabug: 25704090

Reported-by: Ritika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 70bdf2026d905b8bfa0a455d35018df3e9777a6c)
Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: John Sobecki <john.sobecki@oracle.com>
Conflicts:
	drivers/scsi/scsi_debug.c