remove dead iommu code v2

[Christoph Hellwig]

Hi all,

this removes a bit of dead code and methods from the iommu code and the
cleans up the arm-smmu-v3 driver a little bit based on that.

Changes since v1:
 - rebased to the latest iommu/core branch
 - don't accidentally change an error code in arm_smmu_dev_enable_feature
 - add a kerneldoc comment to iommu_put_resv_regions

Diffstat:
 drivers/iommu/amd/iommu.c                   |    1 
 drivers/iommu/apple-dart.c                  |    1 
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |   58 ++++++----------------------
 drivers/iommu/arm/arm-smmu/arm-smmu.c       |    1 
 drivers/iommu/intel/iommu.c                 |    1 
 drivers/iommu/iommu.c                       |   34 +---------------
 drivers/iommu/mtk_iommu.c                   |    1 
 drivers/iommu/virtio-iommu.c                |    5 --
 include/linux/iommu.h                       |   17 --------
 9 files changed, 21 insertions(+), 98 deletions(-)