Wait for AEN task to be completed(if in queue) before resetting the controller
and return without processing event in AEN thread, if controller reset is in progress.

Submitted by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed by: Kashyap Desai <Kashyap.Desai@broadcom.com>
MFC after: 3 days
Sponsored by: Broadcom Limited/AVAGO Technologies