GPS_Backend: make_gps_time增加check_new_itow函数，修复NMEA RTC时间不对问题

libraries/AP_GPS/GPS_Backend.cpp

@@ -107,6 +107,8 @@ void AP_GPS_Backend::make_gps_time(uint32_t bcd_date, uint32_t bcd_milliseconds)
     state.time_week = ret / AP_SEC_PER_WEEK;
     state.time_week_ms = (ret % AP_SEC_PER_WEEK) * AP_MSEC_PER_SEC;
     state.time_week_ms += msec;
+    
+    check_new_itow(state.time_week_ms, 10); // 数据长度先取10，测试时间没问题
 }
 
 /*