msm-perf: Removed game active status node

Removed the support for game status node to specifically compare
for gfx events, the same is archived with checking the value of pid.
This saves an extra fops on each iteration for game on and off.

Rejecting events with timestamp = 0.

Change-Id: Icbafc4d1f8fa1e444b9074fcf2fde47a6e85d609
Signed-off-by: Aman Mehta <amanmeht@codeaurora.org>