x64, x2apic/intr-remap: parse ioapic scope under vt-d structures

Parse the vt-d device scope structures to find the mapping between IO-APICs
and the interrupt remapping hardware units.

This will be used later for enabling Interrupt-remapping for IOAPIC devices.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 4d1ce2e..1c409c7 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -26,6 +26,8 @@
 # Build Intel IOMMU support
 obj-$(CONFIG_DMAR) += dmar.o iova.o intel-iommu.o
 
+obj-$(CONFIG_INTR_REMAP) += dmar.o intr_remapping.o
+
 #
 # Some architectures use the generic PCI setup functions
 #