Split joystick_reader into hardware shim + application.

Change-Id: If31e6dd7ece547a2952ec21e2f4bc745ee6f9d84
diff --git a/aos/prime/input/joystick_input.h b/aos/prime/input/joystick_input.h
index 17fdbbe..c44c5e2 100644
--- a/aos/prime/input/joystick_input.h
+++ b/aos/prime/input/joystick_input.h
@@ -20,6 +20,12 @@
   virtual void RunIteration(const driver_station::Data &data) = 0;
 };
 
+// Class which will proxy joystick information from UDP packets to the queues.
+class JoystickProxy {
+ public:
+  void Run();
+};
+
 }  // namespace input
 }  // namespace aos