msm: kgsl: Use only compat VA range for compat tasks

Set KGSL_MEMFLAGS_FORCE_32BIT for compat tasks in
IOCTL_KGSL_GPUOBJ_ALLOC and IOCTL_KGSL_GPUOBJ_IMPORT
to make sure compat VA range is used. This is required
to avoid allocating a 64bit GPU VA for a 32bit application
running on a 64bit kernel.

Change-Id: I5cc526efd513e099fc7cda747e85e5fd6a8f1a32
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>