ArduCopter: support *10 multipler when storing/retrieving radius in NAV_LOITER_TURNS

ArduCopter/mode_auto.cpp

@@ -1361,7 +1361,12 @@ void ModeAuto::do_circle(const AP_Mission::Mission_Command& cmd)
     const Location circle_center = loc_from_cmd(cmd, copter.current_loc);
 
     // calculate radius
-    uint8_t circle_radius_m = HIGHBYTE(cmd.p1); // circle radius held in high byte of p1
+    uint16_t circle_radius_m = HIGHBYTE(cmd.p1); // circle radius held in high byte of p1
+    if (cmd.id == MAV_CMD_NAV_LOITER_TURNS &&
+        cmd.type_specific_bits & (1U << 0)) {
+        // special storage handling allows for larger radii
+        circle_radius_m *= 10;
+    }
 
     // move to edge of circle (verify_circle) will ensure we begin circling once we reach the edge
     circle_movetoedge_start(circle_center, circle_radius_m);