treewide: Rename customized iommu initialization functions

Certain functionality is being deprecatated in favor of a more
upstream friendly approach. Rename the functions to discourage
future users during the phase-out process.

Change-Id: Iac6f2581f43ecda2325e51be6b2d57a049cb960a
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>