tracing: Remove the stale include/trace/power.h

Commit 61613521

 moved the power tracing to include/trace/events/,
but left the old header behind.  No one is using the old header,
and its declarations are now incorrect, so it should be removed.

Signed-off-by: Josh Stone <jistone@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1258578415-14752-1-git-send-email-jistone@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>