msm: kgsl: Do not allocate memory for profiling and sync commands

Do not allocate memory for IB descriptors for commands
of types profiling buffers, sync and markers.

This fixes the memory leak due to allocation of
memory for such commands and these were never freed.

CRs-Fixed: 996651
Change-Id: Ib168d60ad89e0fd55cd1f10b773b7cdaa7400ace
Signed-off-by: Sunil Khatri <sunilkh@codeaurora.org>