mpt3sas: Use alloc_ordered_workqueue() API instead of create_singlethread_workqueue() API

Created a thread using alloc_ordered_workqueue() API in order to process
the works from firmware Work-queue sequentially instead of
create_singlethread_workqueue() API.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>