msm: kgsl: Avoid AOP message on unsupported A640 GPUs

Do not send AOP messages from A640 GPU targets in which
ACD feature is not supported.

Change-Id: Ia90523acd029bdbb9e5ae39e719f2ac8bdb6640d
Signed-off-by: Harshitha Sai Neelati <hsaine@codeaurora.org>