drm/nouveau/pm: detect when we need dll disabled for gddr3

Fixes minor flickering on NVS295 when at perflvl 0.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Martin Peres <martin.peres@labri.fr>
diff --git a/drivers/gpu/drm/nouveau/nouveau_perf.c b/drivers/gpu/drm/nouveau/nouveau_perf.c
index bd6071f..cc8beb8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_perf.c
+++ b/drivers/gpu/drm/nouveau/nouveau_perf.c
@@ -139,7 +139,7 @@
 	return NULL;
 }
 
-static u8 *
+u8 *
 nouveau_perf_ramcfg(struct drm_device *dev, u32 freq, u8 *ver, u8 *len)
 {
 	struct drm_nouveau_private *dev_priv = dev->dev_private;