drm/amd/display: Fix missing blendTF programming

[Why]
When MPO surface pixel format is not ARGB8888, fast update can miss
programming blendTF.

[How]
Set the gamma_change update flag on blend_tf change.
Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -2582,6 +2582,9 @@ static enum surface_update_type det_surface_update(const struct dc *dc,
 	if (u->gamut_remap_matrix)
 		update_flags->bits.gamut_remap_change = 1;
 
+	if (u->blend_tf)
+		update_flags->bits.gamma_change = 1;
+
 	if (u->gamma) {
 		enum surface_pixel_format format = SURFACE_PIXEL_FORMAT_GRPH_BEGIN;