drm/amd/display: Fix CSC remap matrix not being applied on dcn30

[Why]
DCN3 has two gamut remap matrices. When using CSC adjustment the CM
remap is set to bypass and MPCC remap is used. However to bypass CM
some state in the context is modified and not restored correctly
resulting in subsequent calls to disable MPCC remap as well.

[How]
Fix logic for save/restore of remap enable flag when programming MPCC
remap matrix.
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -1482,22 +1482,23 @@ static void dcn20_update_dchubp_dpp(
 
 			memset(&adjust, 0, sizeof(adjust));
 			adjust.gamut_adjust_type = GRAPHICS_GAMUT_ADJUST_TYPE_BYPASS;
-			/* save the enablement of gamut remap for dpp*/
+
+			/* save the enablement of gamut remap for dpp */
 			enable_remap_dpp = pipe_ctx->stream->gamut_remap_matrix.enable_remap;
-			/*force bypass gamut remap for dpp/cm*/
+
+			/* force bypass gamut remap for dpp/cm */
 			pipe_ctx->stream->gamut_remap_matrix.enable_remap = false;
 			dc->hwss.program_gamut_remap(pipe_ctx);
-			/*restore gamut remap flag for the top plane and use this remap into mpc*/
-			if (pipe_ctx->top_pipe == NULL)
-				pipe_ctx->stream->gamut_remap_matrix.enable_remap = enable_remap_dpp;
-			else
-				pipe_ctx->stream->gamut_remap_matrix.enable_remap = false;
-
-			if (pipe_ctx->stream->gamut_remap_matrix.enable_remap == true) {
-				adjust.gamut_adjust_type = GRAPHICS_GAMUT_ADJUST_TYPE_SW;
-				for (i = 0; i < CSC_TEMPERATURE_MATRIX_SIZE; i++)
-					adjust.temperature_matrix[i] =
-						pipe_ctx->stream->gamut_remap_matrix.matrix[i];
+
+			/* restore gamut remap flag and use this remap into mpc */
+			pipe_ctx->stream->gamut_remap_matrix.enable_remap = enable_remap_dpp;
+
+			/* build remap matrix for top plane if enabled */
+			if (enable_remap_dpp && pipe_ctx->top_pipe == NULL) {
+					adjust.gamut_adjust_type = GRAPHICS_GAMUT_ADJUST_TYPE_SW;
+					for (i = 0; i < CSC_TEMPERATURE_MATRIX_SIZE; i++)
+						adjust.temperature_matrix[i] =
+								pipe_ctx->stream->gamut_remap_matrix.matrix[i];
 			}
 			mpc->funcs->set_gamut_remap(mpc, mpcc_id, &adjust);
 		} else