Rover: added in sitl object, needed for throttle control

APMrover2/Parameters.h

@@ -168,6 +168,9 @@ public:
         k_param_fence_minalt,
         k_param_fence_maxalt,
 
+        // other objects
+        k_param_sitl = 230,
+
         //
         // 240: PID Controllers
         //

APMrover2/Parameters.pde

@@ -125,6 +125,12 @@ const AP_Param::Info var_info[] PROGMEM = {
     GOBJECT(ins,                            "INS_", AP_InertialSensor),
 #endif
 
+#ifdef DESKTOP_BUILD
+    // @Group: SIM_
+    // @Path: ../libraries/SITL/SITL.cpp
+    GOBJECT(sitl, "SIM_", SITL),
+#endif
+
     // @Group: AHRS_
     // @Path: ../libraries/AP_AHRS/AP_AHRS.cpp
     GOBJECT(ahrs,                   "AHRS_",    AP_AHRS),