msm: kgsl: GPU fault tolerance timer

GPU fault tolerance timer with a 50ms interval is introduced to detect
the condition where GPU is stalled, when GPU state is active we check
for GPU stall and if a stall is detected fault tolerance is triggered.
Using a timer is a better design because this removes dependency
on userspace to call waittimestamp.

CRs-Fixed: 477979
Change-Id: I22b1316ad3edb271c1241b93e7a36373dfc70234
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>