[CFT] alc(4) QAC AR816x/AR817x ethernet controller support

[Yonghyeon PYUN]

Hi,
I've added support for QAC AR816x/AR817x ethernet controllers.  It
passed my limited testing and I need more testers.  You can find
patches from the following URLs.

http://people.freebsd.org/~yongari/alc/pci.quirk.diff
and
http://people.freebsd.org/~yongari/alc/alc.diff.20140930

pci.qurik.diff is to workaround silicon bug of AR816x. Without it
MSI/MSIX interrupt wouldn't work.  If you just want to use
legacy INTx interrupt you don't have to apply it but you have to
tell alc(4) not to use MSI/MSIX interrupt with tunables(
hw.alc.msi.disable and hw.alc.msix_disable).

alc.diff.20140930 will add support for AR8161/AR8162/AR8171/AR8172
and E2200 controllers.  It supports all hardware features except
RSS.  If you have any QAC AR816x/AR817x or old AR813x/AR815x
controllers please test and report how the diff works for you.
Thanks.