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

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

BugLink: http://bugs.launchpad.net/bugs/1756094
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>
(cherry picked from commit e402acdb664134f948b62d13b7db866295689f38)
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>