2 reasons:
-no need to keep a list of all known parts
-there is at least 1 bridge (ACC micro 2051) which reports the same
device ID for its various subfunctions; this would require an additional
check in the match function
(keep the old list inside #if 0 in case one of the historical bridges
doesn't report the right class/subclass - I can't check them all)
primarily to nicely print version information about your PCI chipset
(try with "options PCIVERBOSE"). Eventually, it may be used to
enable/disable features/bugs of a given PCI chipset. In addition, this
driver uses the PCI-ISA bridge callback mechanism to logically attach the
ISA bus to the PCI-ISA bridge.
drochner