tracing: Rename ftrace_event.h to trace_events.h

The term "ftrace" is really the infrastructure of the function hooks,
and not the trace events. Rename ftrace_event.h to trace_events.h to
represent the trace_event infrastructure and decouple the term ftrace
from it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/trace/events/power.h

@@ -7,7 +7,7 @@
 #include <linux/ktime.h>
 #include <linux/pm_qos.h>
 #include <linux/tracepoint.h>
-#include <linux/ftrace_event.h>
+#include <linux/trace_events.h>
 
 #define TPS(x)  tracepoint_string(x)