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: I6739b6b69688b98d283d73b3acd21e11ed059cd6
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>