Import QEMU upstream snapshot d2e570c

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

Upstream-Commit: d2e570cc0f97b936902a5b1b86b73c0f5998b475

system/device_tree-stub.c

@@ -0,0 +1,13 @@
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-machine.h"
+
+#ifdef CONFIG_FDT
+void qmp_dumpdtb(const char *filename, Error **errp)
+{
+    ERRP_GUARD();
+
+    error_setg(errp, "This machine doesn't have an FDT");
+    error_append_hint(errp, "(this machine type definitely doesn't use FDT)\n");
+}
+#endif