[POWERPC] Clear pci_probe_only on 64 bits PowerMac
It should now be safe to re-assign unassigned resources on 64 bits PowerMac
machines (G5s). This clears pci_probe_only on those.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>