msm: kgsl: Faster GPU hang detection

Check global GPU status registers in intervals of 2 seconds,
if the registers did not change after 2 seconds trigger a hang.
When there is an actual GPU hang and GPU is stalled, this reduces
the current hang detection time from 10 seconds to 2 seconds.
Faster GPU hang detection reduces the overall time to recover
from GPU hang.

Change-Id: If432ccacc1b77b4fc7f08b756886bd3ae5edf04f
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>