Tracker: consolidate camera dummy functions into system.cpp

AntennaTracker/camera.cpp

@@ -1,13 +0,0 @@
-/* dummy methods to avoid having to link against AP_Camera */
-
-#include <AP_Camera/AP_Camera.h>
-
-namespace AP {
-    AP_Camera *camera() {
-        return nullptr;
-    }
-};
-
-void AP_Camera::take_picture()
-{
-}

AntennaTracker/system.cpp

@@ -277,6 +277,13 @@ void AP_Camera::control_msg(const mavlink_message_t &) {}
 void AP_Camera::configure(float, float, float, float, float, float, float) {}
 void AP_Camera::control(float, float, float, float, float, float) {}
 void AP_Camera::send_feedback(mavlink_channel_t chan) {}
+void AP_Camera::take_picture() {}
+namespace AP {
+    AP_Camera *camera() {
+        return nullptr;
+    }
+};
+
 /* end dummy methods to avoid having to link against AP_Camera */
 
 // dummy method to avoid linking AFS