tracing: combine the default tracers into one config

Both event tracer and sched switch plugin are selected by default
by all generic tracers. But if no generic tracer is enabled, their options
appear. But ether one of them will select the other, thus it only
makes sense to have the default tracers be selected by one option.

[ Impact: clean up kconfig menu ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/Kconfig

@@ -192,27 +192,14 @@ config SCHED_TRACER
 	  This tracer tracks the latency of the highest priority task
 	  to be scheduled in, starting from the point it has woken up.
 
-config ENABLE_CONTEXT_SWITCH_TRACER
-	bool "Trace process context switches"
-	depends on !GENERIC_TRACER
-	select TRACING
-	select CONTEXT_SWITCH_TRACER
-	help
-	  This tracer gets called from the context switch and records
-	  all switching of tasks.
-
-config ENABLE_EVENT_TRACING
-	bool "Trace various events in the kernel"
+config ENABLE_DEFAULT_TRACERS
+	bool "Trace process context switches and events"
 	depends on !GENERIC_TRACER
 	select TRACING
 	help
 	  This tracer hooks to various trace points in the kernel
 	  allowing the user to pick and choose which trace point they
-	  want to trace.
-
-	  Note, all tracers enable event tracing. This option is
-	  only a convenience to enable event tracing when no other
-	  tracers are selected.
+	  want to trace. It also includes the sched_switch tracer plugin.
 
 config FTRACE_SYSCALLS
 	bool "Trace syscalls"