Intel IOMMU Suspend/Resume Support - DMAR

This patch implements the suspend and resume feature for Intel IOMMU
DMAR. It hooks to kernel suspend and resume interface. When suspend happens, it
saves necessary hardware registers. When resume happens, it restores the
registers and restarts IOMMU by enabling translation, setting up root entry, and
re-enabling queued invalidation.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>