drm/amd/display: Do not copy bottom pipe when map resource.

Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1134,6 +1134,9 @@ enum dc_status resource_map_pool_resources(
 			if (!are_stream_backends_same(old_pipe_ctx->stream, stream))
 				continue;
 
+			if (old_pipe_ctx->top_pipe)
+				continue;
+
 			pipe_ctx->stream = stream;
 			copy_pipe_ctx(old_pipe_ctx, pipe_ctx);