MFC r224020:

MFC r224020:
  Add initial support for AX88772B USB Fast Ethernet. AX88772B
  supports IPv4/IPv6 checksum offloading and VLAN tag insertion/
  stripping as well as WOL.  Because uether does not provide a way
  to announce driver specific offload capabilities to upper stack,
  checksum offloading support needs more work and will be done in
  future.
  Special thanks to ASIX for donating sample hardware.

  H/W donated by:	ASIX Electronics
  Reviewed by:		hselasky

git-svn-id: svn://svn.freebsd.org/base/stable/8@224398 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f