msm: kgsl: Get GPU snapshot if wait for global timestamp timeout

If the wait for global fails due to timeout then nothing after this
point is likely to work very well. Get GPU snapshot in addition to
BUG_ON(), to analyze the GPU fault.

CRs-Fixed: 1053780
Change-Id: I29930120a72a08533c859002f646af93e67c754f
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>