During remove() or shutdown(), driver waits for external thread
to complete but there is no mechanism available today to inform
lower layers that driver is about to go through remove() or
shutdown(). Add mechanism to provide the notification about
remove() or shutdown() so that lower layers can make use of it
and get out of waiting logic and complete the remove() or
shutdown() early without waiting for the timeout to happen.
Change-Id: I1eece21fb63e6d5e0454659795a4dad011483c75
CRs-fixed: 1079299
(cherry picked from commit 305516248006141ef331c8c1b7a4b56999fa496d)
f7969a6c2d