Add bfe(4) support from FreeBSD. Initial code submitted by Peter Avalos <pavalos@theshell.com>. Changes to the FreeBSD version: - make the code consistent w.r.t. style(9) - remove some unused entries from bfe_softc - use the PCI IDs from pcidevs.h - use BUS_DMA_WAITOK since the allocation is done in bfe_attach before the interrupt is registered and sleeping is therefore safe - fix some warnings in the code about signed/unsigned comparisions