drm/radeon/kms: reorganize copy callbacks

tidy up the radeon_asic struct, handle multiple
rings better.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König<christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index db09065..6863a05 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -1466,7 +1466,7 @@
 	r = evergreen_blit_init(rdev);
 	if (r) {
 		r600_blit_fini(rdev);
-		rdev->asic->copy = NULL;
+		rdev->asic->copy.copy = NULL;
 		dev_warn(rdev->dev, "failed blitter (%d) falling back to memcpy\n", r);
 	}