These drivers don't support IOMMU_DOMAIN_DMA, so this commit effectively
allows them to support that mode.

The prior work to require default_domains makes this safe because every
one of these drivers is either compilation incompatible with dma-iommu.c,
or already establishing a default_domain. In both cases alloc_domain()
will never be called with IOMMU_DOMAIN_DMA for these drivers so it is safe
to drop the test.

Removing these tests clarifies that the domain allocation path is only
about the functionality of a paging domain and has nothing to do with
policy of how the paging domain is used for UNMANAGED/DMA/DMA_FQ.
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Steven Price <steven.price@arm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/24-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.comSigned-off-by: Joerg Roedel <jroedel@suse.de>