scsi: hpsa: Increase queue depth for external LUNs

Increase queue_depth for PTRAID devices to improve performance.

Link: https://lore.kernel.org/r/159528197765.24772.15623281371636788406.stgit@brunhilda


Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Scott Benesh <scott.benesh@microsemi.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>