drm/vgem: add compat_ioctl support

DRM drivers should supply a compat version if they're going to provide
an ioctl implementation at all. This can confuse 32-bit user space on a
64-bit system.
Signed-off-by: NBrian Norris <briannorris@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170715031212.108695-1-briannorris@chromium.org

drivers/gpu/drm/vgem/vgem_drv.c

@@ -278,6 +278,7 @@ static const struct file_operations vgem_driver_fops = {
 	.poll		= drm_poll,
 	.read		= drm_read,
 	.unlocked_ioctl = drm_ioctl,
+	.compat_ioctl	= drm_compat_ioctl,
 	.release	= drm_release,
 };