drm/nv50: fix minor thinko from nvc0 changes

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_i2c.c b/drivers/gpu/drm/nouveau/nouveau_i2c.c
index 0bd407c..8461485 100644
--- a/drivers/gpu/drm/nouveau/nouveau_i2c.c
+++ b/drivers/gpu/drm/nouveau/nouveau_i2c.c
@@ -163,7 +163,7 @@
 	if (entry->chan)
 		return -EEXIST;
 
-	if (dev_priv->card_type == NV_C0 && entry->read >= NV50_I2C_PORTS) {
+	if (dev_priv->card_type >= NV_50 && entry->read >= NV50_I2C_PORTS) {
 		NV_ERROR(dev, "unknown i2c port %d\n", entry->read);
 		return -EINVAL;
 	}