Remove unused systemTime() and include utils/Timers.h.

Remove a systemTime() function from power/power.c that
doesn't appear to be called anywhere, and make several
audio/ files explicitly include utils/Timers.h for the
libutils version of systemTime(). (They appear to have been
transitively getting it via utils/threads.h's include of
utils/Condition.h.)

Change-Id: I432bb1cf1100f5829df307a146076acf035a0bdc
3 files changed