AP_Baro: fixed example build

libraries/AP_Baro/examples/BARO_generic/BARO_generic.pde

@@ -30,6 +30,9 @@
 #include <AP_HAL_FLYMAPLE.h>
 #include <AP_HAL_PX4.h>
 #include <AP_HAL_Empty.h>
+#include <AP_Rally.h>
+#include <AP_NavEKF.h>
+#include <AP_Scheduler.h>
 
 const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;