iommu: Fixup selftests

Commit fb3f2510 ("iommu/arm-smmu: Merge all IOMMU changes from msm-4.19
to msm-lahaina") added some enhanced selftest functions for io-pgtable-arm
and io-pgtable-fast but they still had older APIs for the IOMMU
operations.

Change-Id: Ic0dedbad3ce8339bc471afb83113b47cd169d5cc
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>