Merge branch 'for-next/iommu/iova' into for-next/iommu/core

IOVA allocator updates for 5.11, including removal of unused symbols and
functions as well as some optimisations to improve allocation behaviour
in the face of fragmentation.

* for-next/iommu/iova:
  iommu: Stop exporting free_iova_mem()
  iommu: Stop exporting alloc_iova_mem()
  iommu: Delete split_and_remove_iova()
  iommu: avoid taking iova_rbtree_lock twice
  iommu/iova: Free global iova rcache on iova alloc failure
  iommu/iova: Retry from last rb tree node if iova search fails