AP_GPS: fixed example builds with change to init()

libraries/AP_GPS/examples/GPS_406_test/GPS_406_test.pde

@@ -27,7 +27,7 @@ void setup()
     hal.uartB->begin(57600, 128, 16);
     gps.print_errors = true;
 
-    gps.init(hal.uartB);  // GPS Initialization
+    gps.init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_4G);  // GPS Initialization
     hal.scheduler->delay(1000);
 }
 void loop()

libraries/AP_GPS/examples/GPS_AUTO_test/GPS_AUTO_test.pde

@@ -35,7 +35,7 @@ void setup()
 
     hal.console->println("GPS AUTO library test");
     gps = &GPS;
-    gps->init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_2G);
+    gps->init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_4G);
 
     // initialise the leds
     board_led.init();

libraries/AP_GPS/examples/GPS_MTK_test/GPS_MTK_test.pde

@@ -30,7 +30,7 @@ void setup()
     gps.print_errors = true;
 
     hal.console->println("GPS MTK library test");
-    gps.init(hal.uartB);  // GPS Initialization
+    gps.init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_4G);  // GPS Initialization
 }
 
 void loop()

libraries/AP_GPS/examples/GPS_NMEA_test/GPS_NMEA_test.pde

@@ -51,7 +51,7 @@ void setup()
     for (uint8_t i = 0; i < sizeof(sirf_to_nmea); i++)
         hal.uartB->write(sirf_to_nmea[i]);
 
-    gps->init(hal.uartB);
+    gps->init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_4G);
 }
 
 void loop()

libraries/AP_GPS/examples/GPS_UBLOX_test/GPS_UBLOX_test.pde

@@ -30,7 +30,7 @@ void setup()
     gps.print_errors = true;
 
     hal.console->println("GPS UBLOX library test");
-    gps.init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_2G);       // GPS Initialization
+    gps.init(hal.uartB, GPS::GPS_ENGINE_AIRBORNE_4G);       // GPS Initialization
 }
 
 void loop()