TF-RMM Release v0.1.0

This is the first external release of TF-RMM and provides a reference
implementation of Realm Management Monitor (RMM) as specified by the
RMM Beta0 specification[1].

The `docs/readme.rst` has more details about the project and
`docs/getting_started/getting-started.rst` has details on how to get
started with TF-RMM.

[1] https://developer.arm.com/documentation/den0137/1-0bet0/?lang=en

Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: I205ef14c015e4a37ae9ae1a64e4cd22eb8da746e
diff --git a/runtime/include/rsi-handler.h b/runtime/include/rsi-handler.h
new file mode 100644
index 0000000..0151229
--- /dev/null
+++ b/runtime/include/rsi-handler.h
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-FileCopyrightText: Copyright TF-RMM Contributors.
+ */
+
+#ifndef RSI_HANDLER_H
+#define RSI_HANDLER_H
+
+unsigned long system_rsi_abi_version(void);
+
+#endif /* RSI_HANDLER_H */