drm/radeon/kms: fix bandwidth computation on avivo hardware

Fix bandwidth computation and crtc priority in memory controller
so that crtc memory request are fullfill in time to avoid display
artifact.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index ab0c967..bccdce7 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -301,6 +301,11 @@
 	rdev->mc.vram_width = 128;
 }
 
+void rs600_bandwidth_update(struct radeon_device *rdev)
+{
+	/* FIXME: implement, should this be like rs690 ? */
+}
+
 
 /*
  * Indirect registers accessor