msm: kgsl: Use GPU to select perfcounters

Use the GPU to set the select register of perfcounter instead
of using the CPU to set the select register. This removes the
synchronization between CPU and GPU where CPU needs to wait for
GPU to idle before setting the perfcounter select register.
Additionally with SP/TP power collapse feature the SP/TP will
automatically power on when GPU is used to set perfcounter
registers hence this feature does not need to be turned off/on when
SP/TP perfcounters are set.

Change-Id: I3f12792ddd44f055e7d3bb803e7bfd3ca49a4158
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>