Merge branch 'for-thierry/arm-smmu' into for-joerg/arm-smmu/updates

Merge in support for the Arm SMMU '->probe_finalize()' implementation
callback, which is required to prevent early faults in conjunction with
Nvidia's memory controller.

* for-thierry/arm-smmu:
  iommu/arm-smmu: Check smmu->impl pointer before dereferencing
  iommu/arm-smmu: Implement ->probe_finalize()