drm/nvd0/disp: implement support for colour vibrance control

Ported from original nv50 commit by Christoph, with added support for the
setting on later chipsets.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index b875fcf..f03b075 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -324,7 +324,7 @@
 	disp->underscan_vborder_property =
 		drm_property_create_range(dev, 0, "underscan vborder", 0, 128);
 
-	if (gen == 1) {
+	if (gen >= 1) {
 		disp->vibrant_hue_property =
 			drm_property_create(dev, DRM_MODE_PROP_RANGE,
 					    "vibrant hue", 2);