msm: kgsl: Correct memory type update in IOCTL_KGSL_GPUOBJ_SET_INFO

A bad user can pass memory type parameter value greater than 255.
Limit the memory type value to valid range before updating memory
descriptor flags to avoid incorrect flag update.

Change-Id: I23ce69584d1e2c9969583461ee942c5046e7cdbc
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>