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.

Conflicts:

    drivers/gpu/msm/adreno.c
    drivers/gpu/msm/kgsl_pwrctrl.c

CRs-Fixed: 477979
Change-Id: I22b1316ad3edb271c1241b93e7a36373dfc70234
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
msm: kgsl: Check long IB only for valid context

Do not check for long IB if the hang is detected in a NULL context,
hang in NULL context can happen when we are switching from NULL to
active context and hang is detected in commands that write an
active context to memstore, long IB in this scenario is not possible.

Change-Id: I7711c86b91c6c2ce0b4aa0543572c26d10c83030
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>