ARM: dts: msm: Increase GPU snapshot size for msm8953

Increase GPU snapshot memory size from 1MB to 2MB for
msm8953 so that more information can be saved in snapshot
which will help to debug GPU hangs.

Change-Id: I4b7b0e2a5b1d04c81ec28327252a538e670047a9
Signed-off-by: Archana Sriram <apsrir@codeaurora.org>