ia64/PCI: register busn_res for root buses

Add the host bridge bus number aperture from _CRS to the resource list.
Like the MMIO and I/O port apertures, this is used when assigning
resources to hot-added devices or in the case of conflicts.

[bhelgaas: changelog]
CC: Tony Luck <tony.luck@intel.com>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: linux-ia64@vger.kernel.org
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/ia64/pci/pci.c

@@ -351,6 +351,8 @@ pci_acpi_scan_root(struct acpi_pci_root *root)
 #endif
 
 	INIT_LIST_HEAD(&info.resources);
+	/* insert busn resource at first */
+	pci_add_resource(&info.resources, &root->secondary);
 	acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window,
 			&windows);
 	if (windows) {
@@ -384,7 +386,7 @@ pci_acpi_scan_root(struct acpi_pci_root *root)
 		return NULL;
 	}
 
-	pbus->busn_res.end = pci_scan_child_bus(pbus);
+	pci_scan_child_bus(pbus);
 	return pbus;
 
 out3: