tracing: Move "display-graph" option to main options

In order to facilitate making all tracer options visible even when the
tracer is not active, we need to get rid of duplicate options. Any option
that is shared between multiple tracers really should be a main option.

As the wakeup and irqsoff tracers both use the "display-graph" option, and
use it exactly the same way, move that option from the tracer options to the
main options and consolidate them.

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

kernel/trace/trace.c

@@ -882,6 +882,7 @@ static const char *trace_options[] = {
 	"irq-info",
 	"markers",
 	"function-trace",
+	"display-graph",
 	NULL
 };