nf: IDLETIMER: time-stamp and suspend/resume handling.

Message notifications contains an additional timestamp field in nano seconds.
The expiry time for the timers are modified during suspend/resume.
If timer was supposed to expire while the system is suspended then a
notification is sent when it resumes with the timestamp of the scheduled expiry.

Removes the race condition for multiple work scheduled.

Bug: 13247811

Change-Id: I52fdd2800aaf88e477df1228474b4965a9397450
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>