Copter: move SmartRTLState to SmartRTL class

ArduCopter/defines.h

@@ -91,15 +91,6 @@ enum class AirMode {
     AIRMODE_ENABLED,
 };
 
-// Safe RTL states
-enum class SmartRTLState : uint8_t {
-    WAIT_FOR_PATH_CLEANUP,
-    PATH_FOLLOW,
-    PRELAND_POSITION,
-    DESCEND,
-    LAND
-};
-
 enum PayloadPlaceStateType {
     PayloadPlaceStateType_FlyToLocation,
     PayloadPlaceStateType_Calibrating_Hover_Start,

ArduCopter/mode.h

@@ -1237,6 +1237,15 @@ public:
 
     bool is_landing() const override;
 
+    // Safe RTL states
+    enum class SmartRTLState : uint8_t {
+        WAIT_FOR_PATH_CLEANUP,
+        PATH_FOLLOW,
+        PRELAND_POSITION,
+        DESCEND,
+        LAND
+    };
+
 protected:
 
     const char *name() const override { return "SMARTRTL"; }