small cleanup
uups
move vivante_gpu_3d_init(..) to msm_gpu.c

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
add stub impl for vivante_get_param(..)

this ioctl will be used later to get e.g. chip identity.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>