drm/nouveau/kms/nv50-: enable modern color management properties

For GF119:GV100, we can enable DEGAMMA/CTM/GAMMA. For earlier GPUs, as
there is no CTM, having both degamma and gamma is a bit pointless. Later
GPUs currently lack an implementation.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/dispnv50/head.c

@@ -512,6 +512,11 @@ nv50_head_create(struct drm_device *dev, int index)
 				  &nv50_head_func, "head-%d", head->base.index);
 	drm_crtc_helper_add(crtc, &nv50_head_help);
 	drm_mode_crtc_set_gamma_size(crtc, 256);
+	if (disp->disp->object.oclass >= GF110_DISP &&
+	    disp->disp->object.oclass < GV100_DISP)
+		drm_crtc_enable_color_mgmt(crtc, 256, true, 256);
+	else
+		drm_crtc_enable_color_mgmt(crtc, 0, false, 256);
 
 	if (head->func->olut_set) {
 		ret = nv50_lut_init(disp, &drm->client.mmu, &head->olut);