GCS_MAVLink: move handling of do_send_banner up

libraries/GCS_MAVLink/GCS.h

@@ -298,6 +298,7 @@ protected:
     MAV_RESULT handle_command_mag_cal(const mavlink_command_long_t &packet);
     MAV_RESULT handle_command_long_message(mavlink_command_long_t &packet);
     MAV_RESULT handle_command_camera(const mavlink_command_long_t &packet);
+    MAV_RESULT handle_command_do_send_banner(const mavlink_command_long_t &packet);
 
     // vehicle-overridable message send function
     virtual bool try_send_message(enum ap_message id);

libraries/GCS_MAVLink/GCS_Common.cpp

@@ -2019,12 +2019,23 @@ MAV_RESULT GCS_MAVLINK::handle_command_request_autopilot_capabilities(const mavl
     return MAV_RESULT_ACCEPTED;
 }
 
+
+MAV_RESULT GCS_MAVLINK::handle_command_do_send_banner(const mavlink_command_long_t &packet)
+{
+    send_banner();
+    return MAV_RESULT_ACCEPTED;
+}
+
 MAV_RESULT GCS_MAVLINK::handle_command_long_message(mavlink_command_long_t &packet)
 {
     MAV_RESULT result = MAV_RESULT_FAILED;
 
     switch (packet.command) {
 
+    case MAV_CMD_DO_SEND_BANNER:
+        result = handle_command_do_send_banner(packet);
+        break;
+
     case MAV_CMD_DO_START_MAG_CAL:
     case MAV_CMD_DO_ACCEPT_MAG_CAL:
     case MAV_CMD_DO_CANCEL_MAG_CAL: {