scsi: pm80xx: Remove global lock from outbound queue processing

Introduce spin lock for outbound queue. With this, driver need not acquire
HBA global lock for outbound queue processing.

Link: https://lore.kernel.org/r/20210415103352.3580-9-Viswas.G@microchip.com


Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>