From FreeBSD via OpenBSD, port to NetBSD done by Stephen Degler
Changes relative to submitted version:
* yukonreg.h and xmaciireg.h merged into if_skreg.h
* bhack[] constified + other small editing changes
* use 'Ethernet address' rather than 'address' in attach message
XXX completely untested by me, needs further cleanup
Driver provided in PR kern/22511 by Stephen Degler