msm: kgsl: Migrate SCM calls in kgsl iommu

Adding APIs to check if KGSL SMMU is available, and programming the
SMMU Aperture size. Migrating SCM calls in the KGSL IOMMU driver.

Change-Id: I77178f3e300112fa47a8ca6861acb08d547c9875
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Signed-off-by: Elliot Berman <eberman@codeaurora.org>