Dump IOMMU p2m table

Dump IOMMU p2m table

New key handler 'o' to dump the IOMMU p2m table for each domain.
Skips dumping table for domain 0.
Intel and AMD specific iommu_ops handler for dumping p2m table.

Incorporated feedback from Jan Beulich and Wei Wang.
Fixed indent printing with %*s.
Removed superflous superpage and other attribute prints.
Make next_level use consistent for AMD IOMMU dumps. Warn if found
inconsistent.
AMD IOMMU does not skip levels. Handle 2mb and 1gb IOMMU page size for
AMD.

Signed-off-by: Santosh Jodh <santosh.jodh@citrix.com>
Committed-by: Keir Fraser <keir@xen.org>