Hello!

I removed the config option, added documentation to
Documentation/networking/netdevices.txt
and created a new patch for the new net device feature.

One thought: if you have to add a new field to struct netdevice,
it makes lots of sense to move further and to add special method
dev->generate_eui64() instead, which will be initialized
to standard eth_generate_eui64() for normal ethernets
and to something private for your device.

In this way we are guaranteed not to have problems of this kind
in future.

Alexey