scsi: lpfc: Fix driver not setting dpp bits correctly in doorbell word

Driver is incorrectly formatting a register on new hardware, using a format
for an older chip. This can result in non-deterministic behavior.

Ensure driver is not setting "workqueue index" in the WQ doorbell when
making a non-dpp doorbell write. The field must be zero when non-dpp.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>