Add tracepoints to v4l2reader for ftrace

This makes it easier to trace what is happening in the kernel.

Change-Id: Ie016f1a0bfdfd52cf143bdf1d754ebd366992392
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/frc971/vision/v4l2_reader.h b/frc971/vision/v4l2_reader.h
index e813a00..a2b4c25 100644
--- a/frc971/vision/v4l2_reader.h
+++ b/frc971/vision/v4l2_reader.h
@@ -6,6 +6,7 @@
 
 #include "absl/types/span.h"
 #include "aos/events/event_loop.h"
+#include "aos/ftrace.h"
 #include "aos/scoped/scoped_fd.h"
 #include "frc971/vision/vision_generated.h"
 #include "glog/logging.h"