temporarily revert bus config order back to isa->eisa->pci
until port allocation/accounting is ready (XXX).
works around problem of the if_ep driver's probe function trashing
an adaptec 2940 if the BIOS maps it in at port 0xf000. (the
BIOS on my new P166 does this, ... the BIOS on my P133's does not).
without this the P166 system will reset as soon as spl0() is called
(autoconf.c) making it impossible to install the OS.