ftrace: set up trace event hash infrastructure

Impact: simplify/generalize/refactor trace.c

The trace.c file is becoming more difficult to maintain due to the
growing number of events. There is several formats that an event may
be printed. This patch sets up the infrastructure of an event hash to
allow for events to register how they should be printed.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/trace_power.c

@@ -16,6 +16,7 @@
 #include <linux/module.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 static struct trace_array *power_trace;
 static int __read_mostly trace_power_enabled;