Import QEMU upstream snapshot d2e570c

Upstream: https://gitlab.com/qemu-project/qemu.git

Upstream-Commit: d2e570cc0f97b936902a5b1b86b73c0f5998b475

stubs/fw_cfg.c

@@ -0,0 +1,21 @@
+/*
+ * fw_cfg stubs
+ *
+ * Copyright (c) 2019 Red Hat, Inc.
+ *
+ * Author:
+ *   Philippe Mathieu-Daudé
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/nvram/fw_cfg.h"
+
+const char *fw_cfg_arch_key_name(uint16_t key)
+{
+    return NULL;
+}