bcusdk-clock_gettime.patch (http://knx-user-forum.de/247918-post29.html)
- Renames clock_gettime() in bcusdk; otherwise, it is accidentally used by
  libpthsem, which leads to an endless recursion (clock_gettime -->
  pth_int_time --> pth_time_set --> pth_get_int_time --> my_clock_gettime -->
  clock_gettime).
