drm: mark dma setup/teardown as legacy systems

And hide the checks a bit better. This was already disallowed for
modesetting drivers, so no functinal change here.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 72acae9..f343234 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -60,15 +60,9 @@
 	atomic_set(&dev->ioctl_count, 0);
 	atomic_set(&dev->vma_count, 0);
 
-	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
-	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
-		dev->buf_use = 0;
-		atomic_set(&dev->buf_alloc, 0);
-
-		i = drm_dma_setup(dev);
-		if (i < 0)
-			return i;
-	}
+	i = drm_legacy_dma_setup(dev);
+	if (i < 0)
+		return i;
 
 	for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
 		atomic_set(&dev->counts[i], 0);