iommu/arm-smmu-v3: Remove arm_smmu_domain_finalise() during attach

Domains are now always finalized during allocation because the core code
no longer permits a NULL dev argument to domain_alloc_paging/_flags().

Remove the late finalize during attach that supported domains that were
not fully initialized.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v1-0bb8d5313a27+27b-smmuv3_paging_flags_jgg@nvidia.com


Signed-off-by: Will Deacon <will@kernel.org>