msm: kgsl: clear fault to avoid race between timeout and hard fault

Observed race between timeout fault (long IB detection) and
MISC hang (hard fault). MISC hang can be set while in recovery from
timeout fault. If fault flag is set in start path CP init fails.
Clear gpu fault to avoid such race.

Change-Id: Id99dcefd0ef3438bc95c6c3c84e2eadce214cf77
Signed-off-by: Pranav Patel <pranavp@codeaurora.org>