iommu/arm-smmu: Prepare for multiple DMA domain types

In preparation for the strict vs. non-strict decision for DMA domains to
be expressed in the domain type, make sure we expose our flush queue
awareness by accepting the new domain type.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/8f217ef285bd0bb9456c27ef622d2efdbbca1ad8.1628682049.git.robin.murphy@arm.com


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