Backport bge changes from 8.4-rc1

While pfsense 2.1 fails to install with broadcom bcm5719 4x nic and there are link issues with broadcom bcm5720 2x nic on a dell r420, freebsd 8.4-rc1 seems to be working without problems. By the time i have a timeframe to test the actual hardware, here is a backport
which might help others in the meantime. Not tested on actual hardware, but applies and builds fine.

It is r248860 minus a couple of PCI definition changes.