ANDROID: GKI: kernel: tick-sched: Add an API for wakeup callbacks

Some modules perform actions on wake, as checked in tick-sched. Add a
function to register callbacks and export it.

Bug: 161415027
Bug: 161414381
Signed-off-by: J. Avila <elavila@google.com>
Change-Id: I7e1da4aea9e78ad2a7f0c407d4162fabc0e368a7