Fix a timing issue with the wired driver.

After configuring the interface, wait for the link to become active.
Many ethernet drivers reset the chip when we set multicast filters
(causing significant delays due to link re-negotiation) and, by the time
we start sending packets, they are discared instead of going to the ether.

Tested by:	dumbbell
Add a missing module version declaration to if_tun(4).

PR:		181078
Submitted by:	Brandon Gooch <jamesbrandongooch@gmail.com>
MFC after:	1 week