scsi: hisi_sas: Reduce some indirection in v3 hw driver

Sometimes local functions are called indirectly from the hw driver, which
only makes the code harder to follow. Remove these.

Method .hw_init is only called from platform driver probe, which is not
relevant, so don't set this either.

Link: https://lore.kernel.org/r/1606207594-196362-2-git-send-email-john.garry@huawei.com


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