drm/nouveau: Associate memtimings with performance levels on cards <= nv98

v2 (Ben Skeggs): fix ramcfg strap, and remove bogus handling of perf 0x40

Signed-off-by: Martin Peres <martin.peres@ensi-bourges.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_mem.c b/drivers/gpu/drm/nouveau/nouveau_mem.c
index ce3cb5e..2960f58 100644
--- a/drivers/gpu/drm/nouveau/nouveau_mem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_mem.c
@@ -704,6 +704,7 @@
 
 			/* XXX: reg_100240? */
 		}
+		timing->id = i;
 
 		NV_DEBUG(dev, "Entry %d: 220: %08x %08x %08x %08x\n", i,
 			 timing->reg_100220, timing->reg_100224,
@@ -715,7 +716,7 @@
 	}
 
 	memtimings->nr_timing = entries;
-	memtimings->supported = true;
+	memtimings->supported = (dev_priv->chipset <= 0x98);
 }
 
 void