For software initiated address translation, when domain type is
IOMMU_DOMAIN_IDENTITY i.e SMMU is bypassed, mimic HW behavior
i.e return the same IOVA as translated address.

This patch is an extension to Will Deacon's patchset
"Implement SMMU passthrough using the default domain".
Signed-off-by: NSunil Goutham <sgoutham@cavium.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>