iz list command not working correctly when a lowpan0 interface exists

Hello,

I noted that iz list never returns the proper result (or any result) 
when 6lowpan is loaded and a lowpan0 interface exists. This is true for 
the Linus' git tree (at least in 
rev:0034102808e0dbbf3a2394b82b1bb40b5778de9e, but I haven't seen any 
changes in the more recent revisions).

Here are the steps to reproduce the "bug":
> modprobe fakehard
> modprobe 6lowpan
> iz add wpan-phy0
> ip link set hardwpan0 address ca:fe:ca:fe:ca:fe:ca:fe
> ifconfig hardwpan0 up
> izcoordinator -i hardwpan0 -s 1 -p 777 -c 11 -l lease &
> ip link add link hardwpan0 name lowpan0 type lowpan
> ip link set lowpan0 address de:ad:be:ef:ca:fe:ca:fe
> ip link set lowpan0 up
> iz list

I hooked a debugger to the kernel. The problem lies in the 
ieee802154_dump_iface() function, at the line 262:
> phy = ieee802154_mlme_ops(dev)->get_phy(dev);

Here, function ieee802154_mlme_ops(dev) always returns NULL, because 
the 6lowpan module does not register dev->ml_priv (and set 
ARPHRD_IEEE802154 as dev->type value).

Maybe this is not the proper list to report the bug (given that the 
6lowpan code is now part of the mainstream kernel). In that case, please