iommu/amd: Implement iommu_ops->def_domain_type call-back

Implement the new def_domain_type call-back for the AMD IOMMU driver.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200429133712.31431-4-joro@8bytes.org


Signed-off-by: Joerg Roedel <jroedel@suse.de>