fix SetServo makro and servo_switch module for sim

sw/airborne/actuators.h

@@ -50,4 +50,7 @@ extern uint16_t actuators[SERVOS_NB];
 
 #endif /* ACTUATORS */
 
+// define empty SetServo makro for sim
+#define SetServo(x, v) {}
+
 #endif /* ACTUATORS_H */

sw/airborne/modules/servo_switch/servo_switch.c

@@ -22,6 +22,7 @@
  */
 
 #include "servo_switch/servo_switch.h"
+#include "airframe.h"
 #include "actuators.h"
 
 bool_t servo_switch_on;