This reverts commit ef7c34c1d1.
The commit seems to break all buildbots with messages like:
/builder/shared-workdir/build/include/toplevel.mk:15:
/builder/shared-workdir/build/include/toplevel-vars.mk: No such file or directory
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>