msm: kgsl: Increase the size of the snapshot for A660

Increase the snapshot size in A660 from 1MB to 2MB,
if the allocation fails fallback to 1MB.

Change-Id: I2186a1547d6ffc51060e3bd8cafb45c65ac270b1
Signed-off-by: Urvashi Agrawal <urvaagra@codeaurora.org>