The various *8168 and friends among kernel modules
have finally been pushed into a designated target
so that RM doesn't have to care which particular
additional ethernet modules are available in this
particular branch and kernel.

Tweak distros as appropriate.

NB: *maybe* this is required by distro/.base either.

un-def was a desperate measure when std-def of the day
was suddenly plain broken.

This reverts 0e8871e7.

Shame on me, these shouldn't get forgotten in the first place.