The first board generation of Power Mac G4 ("Yikes!", those with PCI
graphics) still had a PCILynx controller like their G3 predecessors,
but not the later AGP models.  (Jonathan Woithe recalls to have heard
of it, and some web sources reinforce it.)
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>