scsi: lpfc: Work around NVME cmd iu SGL type

The hardware offload for NVME commands was created when the
FC-NVME standard was setting SGL Descriptor Type to SGL Data
Block Descriptor (0h) and SGL Descriptor Sub Type to Address (0h).

A late change in NVMe-over-Fabrics obsoleted these values, creating
a transport SGL descriptor type with new values to go into these
fields.

For initial hardware support, in order to be compliant to the spec,
use host-supplied cmd IU buffers instead of the adapter generated
values. Later hardware will correct this.

Add a module parameter to override this offload disablement if looking
for lowest latency. This is reasonable as nothing in FC-NVME uses
the SQE SGL values.

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

drivers/scsi/lpfc/lpfc_hw4.h

@@ -2678,6 +2678,7 @@ struct lpfc_mbx_read_rev {
 #define lpfc_mbx_rd_rev_vpd_MASK		0x00000001
 #define lpfc_mbx_rd_rev_vpd_WORD		word1
 	uint32_t first_hw_rev;
+#define LPFC_G7_ASIC_1				0xd
 	uint32_t second_hw_rev;
 	uint32_t word4_rsvd;
 	uint32_t third_hw_rev;