msm: kgsl: Fix skipping aperture programming

During the first adreno_start(), we initialize the global PT and
make an scm call to program the aperture related registers. This
programing is skipped when scm_is_call_available() call fails.
Skipping aperture programing can make CP get stuck during a
context switch. To fix this, avoid scm_is_call_available() call
and force aperture programing from secure world for all a6xx GPUs.

Change-Id: I13923afbece0be12b1a9336b7d20c3039164a6b6
Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>