Otherwise NetworkManager (and iproute alike) is not able to identify the
parent IEEE 802.15.4 interface of a 6LoWPAN link.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>