msm: kgsl: Fix guilty context logic for GPU hangs

Always mark GPU contexts that have cause a GPU hang as guilty.
If the GPU context recovered successfully, still mark it as guilty.
This will inform applications that something might have
gone wrong and to take actions to ensure everything is correct.

Also, swap out any active context following a hang.  This will
ensure that any new submissions will force the context to be restored
before it is used.

CRs-fixed: 427603
CRs-fixed: 405434
Change-Id: I6b7cf2b2a680a4691f45535a147ca678a4d961f3
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>