For v3 hw, we support DIF operation for SAS, but not SATA.

In addition, DIF CRC16 is supported.

This patchset adds the SW support for the described features. The main
components are as follows:

- Get protection mask from module param
- Fill PI fields
- Fill related to DIF in DQ and protection iu memories
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>