scsi: hisi_sas: Add support for DIX feature for v3 hw

This patch adds support for DIX to v3 hw driver.

For this, we build upon support for DIF, most significantly is adding new
DMA map and unmap paths.

Some pre-existing macro precedence issues are also tidied. They were
detected by checkpatch --strict.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>