drm: add vblank event trace point

Emit a trace point for vblank events.  This can be helpful for mapping
drawing activity against the vblank frequency and period.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_trace_points.c b/drivers/gpu/drm/drm_trace_points.c
new file mode 100644
index 0000000..0d0eb90
--- /dev/null
+++ b/drivers/gpu/drm/drm_trace_points.c
@@ -0,0 +1,4 @@
+#include "drmP.h"
+
+#define CREATE_TRACE_POINTS
+#include "drm_trace.h"