ACPI: pci_root: pass acpi_pci_root to arch-specific scan

The acpi_pci_root structure contains all the individual items (acpi_device,
domain, bus number) we pass to pci_acpi_scan_root(), so just pass the
single acpi_pci_root pointer directly.

This will make it easier to add _CBA support later.  For _CBA, we need the
entire downstream bus range, not just the base bus number.  We have that in
the acpi_pci_root structure, so passing the pointer makes it available to
the arch-specific code.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index e311602..0b7882d 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -229,8 +229,11 @@
 	return;
 }
 
-struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int domain, int busnum)
+struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
 {
+	struct acpi_device *device = root->device;
+	int domain = root->segment;
+	int busnum = root->secondary.start;
 	struct pci_bus *bus;
 	struct pci_sysdata *sd;
 	int node;