x86/PCI: make pci=lastbus=255 work when acpi is on

Impact: scan more peer root buses even acpi is used

Move pci_bios_fixup_peer_bridges out of pci_legacy_init and into
pci_subsys_init.  This allows pci_bios_fixup_peer_bridges to be called
even pci_apci_init is driving PCI initialization.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

arch/x86/pci/legacy.c

@@ -50,8 +50,6 @@ static int __init pci_legacy_init(void)
 	if (pci_root_bus)
 		pci_bus_add_devices(pci_root_bus);
 
-	pcibios_fixup_peer_bridges();
-
 	return 0;
 }
 
@@ -67,6 +65,7 @@ int __init pci_subsys_init(void)
 	pci_visws_init();
 #endif
 	pci_legacy_init();
+	pcibios_fixup_peer_bridges();
 	pcibios_irq_init();
 	pcibios_init();