Add initial STATE migration code

fido2/data_migration.h

@@ -0,0 +1,15 @@
+// Copyright 2019 SoloKeys Developers
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+#ifndef FIDO2_PR_DATA_MIGRATION_H
+#define FIDO2_PR_DATA_MIGRATION_H
+
+#include "storage.h"
+
+void do_migration_if_required(AuthenticatorState* state_current);
+
+#endif //FIDO2_PR_DATA_MIGRATION_H