scsi: hisi_sas: relocate some common code for v3 hw

scsi: hisi_sas: relocate some common code for v3 hw

BugLink: https://bugs.launchpad.net/bugs/1794166
Much code of PM suspend function also exists in soft reset function. This
is not concise. So, this patch relocates the common code of these two
functions to a separate function.

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 e8ce775e516957a8eb79890c4051796daa4c6f4b)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>