Remove the final users of robot_state and joystick_state

This means we can remove them from the .q file.

Change-Id: Iefded3cf4537b2635341f3248c5f50af1534a241
diff --git a/aos/events/event-loop.h b/aos/events/event-loop.h
index 90eb721..c827c46 100644
--- a/aos/events/event-loop.h
+++ b/aos/events/event-loop.h
@@ -34,6 +34,8 @@
 template <typename T>
 class Sender {
  public:
+  typedef T Type;
+
   Sender() {}
 
   // Represents a single message about to be sent to the queue.