drm/msm: bail out late_init_minor() if it is not a GPU device

Both perf and hangrd make sense only for GPU devices. Bail out if we are
registering a KMS-only device.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/662583/


Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>