Add new USB IDs.

Submitted by:	G'abor Zahemszky <gabor@zahemszky.hu>
MFC after:	1 week
After r274205 unbreak NOIP kernels.  vsi is now also used outside
address family specific blocks so move it out from under the condition.

MFC after:	6 days
X-MFC with:	r274205
Pass mbuf to pfil processing before stripping outer IP header as it
is described in if_enc(4).

MFC after:	2 week
Sponsored by:	Yandex LLC
Remove struct arpcom. It is unused by most interface types, that allocate
it, except Ethernet, where it carried ng_ether(4) pointer.
For now carry the pointer in if_l2com directly.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.