iommu/amd: Do not force direct mapping when SME is active

Do not force devices supporting IOMMUv2 to be direct mapped when memory
encryption is active. This might cause them to be unusable because their
DMA mask does not include the encryption bit.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200824105415.21000-2-joro@8bytes.org


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