msm: kgsl: Add scm call for SMMU aperture programming

For truly dynamic context bank allocation/mapping to work, we
need to set the aperture register CP utilizes to the SMMU
context bank we receive. This aperture register is protected so
we use a new scm call for trustzone to do this for us.

Change-Id: I50ba3d8f4287f3cc251bbce14db4702e1c8f7ebc
Signed-off-by: Shrenuj Bansal <shrenujb@codeaurora.org>