GKI cleanup - Moved struct TIMER_LIST_ENT to OSI

* Moved struct TIMER_LIST_ENT to file osi/include/non_repeating_timer.h
  and renamed it to timer_entry_t
  NOTE: This is a short-term solution. timer_entry_t should be
  removed, and its usage everywhere should be replaced by
  struct non_repeating_timer_t .
* Renamed TIMER_CBACK to timer_callback_t
* Renamed TIMER_PARAM_TYPE to timer_param_t

Change-Id: I9ca830718bf900195f9c0a513a97f6995322693b