msm: kgsl: Limit snapshot when GMU fails to boot

The GMU boots first thing. If this fails then not everything
will be setup and ready for snapshots. Limit the snapshot for
GMU boot failures.

Change-Id: I8db1d66ed89a1562401c707ce4997ee3df1d2c45
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>