drm/amd/display: Fix DML validation of simple vs native 422 modes

[Why]
We're always validating DML with simple 422 DSC even if native 422 DSC
is in use.

[How]
Use the mode configuration from the timing.
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Bindu Ramamurthy <bindur12@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_resource.c

@@ -2201,10 +2201,11 @@ int dcn20_populate_dml_pipes_from_context(
 			pipes[pipe_cnt].dout.output_bpp = (output_bpc * 3.0) / 2;
 			break;
 		case PIXEL_ENCODING_YCBCR422:
-			if (true) /* todo */
-				pipes[pipe_cnt].dout.output_format = dm_s422;
-			else
+			if (res_ctx->pipe_ctx[i].stream->timing.flags.DSC &&
+			    !res_ctx->pipe_ctx[i].stream->timing.dsc_cfg.ycbcr422_simple)
 				pipes[pipe_cnt].dout.output_format = dm_n422;
+			else
+				pipes[pipe_cnt].dout.output_format = dm_s422;
 			pipes[pipe_cnt].dout.output_bpp = output_bpc * 2;
 			break;
 		default: