ion: msm: Add support for secure allocations for the Trusted UI(TUI) VMID

Add the support necessary to allow secure allocations for the
TUI VMID with R/W permissions.

Change-Id: I7486d75b3d9d3f7fa29a8d4972cca671d55b3569
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>