device tree for PCI controllers and make them known to the bus manager,
if we know how to talk with them. ATM we support only the UniNorth chip,
which can be found in G4 Macs (code ported from FreeBSD).
As far as I can judge it, all attached devices are identified correctly
on all three host bridges of my Mac mini.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16102 a95241bf-73f2-0310-859d-f6bbb57e9c96