msm: kgsl: Use CP crash script to save register values on GPU hang

Use CP crash script to dump register state while collecting snapshot
on GPU hang. This feature would replace using CPU to read register
values while collecting snaphot.

Change-Id: Ie2a8138a53c06b6f447fb1081d29a018f89819ce
Signed-off-by: Lokesh Batra <lbatra@codeaurora.org>