[IA64] Make PCI Express support selectable

When I tried to use PCI Express Hotplug driver on my ia64 box, I
noticed that "PCI Express support" is not even selectable on ia64.
This patch makes PCI Express support selectable.
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

arch/ia64/Kconfig

@@ -449,6 +449,8 @@ config PCI_DOMAINS
 	bool
 	default PCI
 
+source "drivers/pci/pcie/Kconfig"
+
 source "drivers/pci/Kconfig"
 
 source "drivers/pci/hotplug/Kconfig"