parisc/PCI: lba: deal with LMMIO/PAT overlaps before creating PCI root bus

This moves the truncate_pat_collision() call out of the pcibios_fixup_bus()
path so that when a future patch builds a list of root bus resources for
pci_create_bus(), it can use the truncated LMMIO range.

truncate_pat_collision() used to be called in this path:

    pci_scan_bus_parented
      pci_create_bus
      pci_scan_child_bus
        pcibios_fixup_bus
	  lba_fixup_bus
	    truncate_pat_collision

All of the PAT and lba_dev resource setup must be done before we call
pci_scan_bus_parented(), so it should be safe to move the
truncate_pat_collision() to just before pci_scan_bus_parented().

CC: linux-parisc@vger.kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>