msm: kgsl: Add other param initialization for gpumem_get_info

Not all the variables in param were initialized in the
gpumem_get_info_compat function. This would result in problems if
those variables are also not set in the main ioctl function.

Change-Id: I21dbd0b2de7acf938436646e8691613ac4b85946
Signed-off-by: Shrenuj Bansal <shrenujb@codeaurora.org>