(1) remove the 'UNSUPP' keyword from the device list,
because it can't be reasonably used (becuase different
devices may be supported on different machines, for
good reason).
(2) enhance pci_devinfo so that class/subclass information
is optional (so pci_devinfo can be used by drivers that
match classes of devices, and want to look up the
devices' names easily).
(3) more known vendors and devices.
(pci_attach_subdev()). remove pciattach() function and the pcicd cfdriver
struct, the former because thre are a lot of attachment actions which really
are machine-dependent (perhaps even "most"), and the latter because now that
both pcimatch() and pciattach() are machine-dependent it's bad style to
declare them here and it gains nothing.