msm: kgsl: Update GMU hang processing in adreno_stop

Ensures GMU snapshot is dumped after detecting GMU hang.
GMU snapshot is required to debug GMU problems. In cases of
GMU hangs, ensure adreno_stop run to the end. Otherwise,
kernel may panic.

Change-Id: I4cde1b48caad501fa90548084df34d09e94a2615
Signed-off-by: George Shen <sqiao@codeaurora.org>