Revert "iommu: Add msm_iommu_ops for qcom specific IOMMU ops"

This reverts commit bf2f3f95.
The structures that were added were not used, so remove them.

Change-Id: Ib29f770bc44c538d3242544477477c8390b83a54
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>