scsi: hisi_sas: add an mechanism to do reset work synchronously

scsi: hisi_sas: add an mechanism to do reset work synchronously

Sometimes it is required to know when the controller reset has completed and
also if it has completed successfully.  For such places, we call
hisi_sas_controller_reset() directly before. That may lead to multiple calls
to this function.

This patch create a per-reset structure which contains a completion structure
and status flag to know when the reset completes and also the status. It is
also in hisi_hba.wq to do reset work.

As all host reset works are done in hisi_hba.wq, we don't worry multiple calls
to hisi_sas_controller_reset().

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>