Implemented interrupt Config Hook in mrsas(4) to defer some of the tasks, like:
riegistering AEN, creating cdev.
Submitted by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed by: Kashyap Desai <Kashyap.Desai@broadcom.com>
MFC after: 3 days
Sponsored by: AVAGO Technologies