iommu: msm: Add support for dynamic domain switch

Dynamic domains are used by clients like KGSL for
very fast switching of page tables for different
processes during per-process page table use-cases.

Add support for attach/detach of dynamic domains
to MSM IOMMU driver.

Change-Id: I6c9118f2be2fc883db00be31255f1e162a377128
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>