scsi: hisi_sas: add v3 hw DFX feature

Realise get_events() to add DFX feature for v3 hw. Just like v2 hw, We
support the following errors:
- loss_of_dword_sync_count
- invalid_dword_count
- phy_reset_problem_count
- running_disparity_error_count

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>