drm/amd/display: Gamut remap only changes missed

[WHY&HOW]
If surface format is dynamically changed within app without changing
timing / whole plane, we don't reprogram gamut remap matrix.

Issue example:
Linear FP16 scRGB going to PQ+BT.2020 monitor.
Remap = scRGB->BT.2020

App switches swapchain format to 10-bit PQ+BT.2020.
SW calculates correctly that new Remap = bypass (in=-out=BT.2020).
But update not applied in HW.
Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Krunoslav Kovac <krunoslav.kovac@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/dcn20/dcn20_hwseq.c

@@ -1638,6 +1638,7 @@ static void dcn20_update_dchubp_dpp(
 	if (pipe_ctx->update_flags.bits.enable || pipe_ctx->update_flags.bits.opp_changed
 			|| pipe_ctx->update_flags.bits.plane_changed
 			|| pipe_ctx->stream->update_flags.bits.gamut_remap
+			|| plane_state->update_flags.bits.gamut_remap_change
 			|| pipe_ctx->stream->update_flags.bits.out_csc) {
 		/* dpp/cm gamut remap*/
 		dc->hwss.program_gamut_remap(pipe_ctx);