iommu/vt-d: Introduce helper function dmar_walk_resources()

Introduce helper function dmar_walk_resources to walk resource entries
in DMAR table and ACPI buffer object returned by ACPI _DSM method
for IOMMU hot-plug.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --cc drivers/iommu/dmar.c
Simple merge

diff --cc drivers/iommu/intel-iommu.c
Simple merge

diff --cc include/linux/dmar.h
Simple merge