mbedTLS: add version 2.1.1

PolarSSL has been renamed to "mbed TLS" and version 2.0 dropped backwards
compatibility. This commit adds only the necessary files without any
modifications, so it doesn't compile yet.

Externals/mbedtls/library/version.c

@@ -0,0 +1,50 @@
+/*
+ *  Version information
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_VERSION_C)
+
+#include "mbedtls/version.h"
+#include <string.h>
+
+unsigned int mbedtls_version_get_number()
+{
+    return( MBEDTLS_VERSION_NUMBER );
+}
+
+void mbedtls_version_get_string( char *string )
+{
+    memcpy( string, MBEDTLS_VERSION_STRING,
+            sizeof( MBEDTLS_VERSION_STRING ) );
+}
+
+void mbedtls_version_get_string_full( char *string )
+{
+    memcpy( string, MBEDTLS_VERSION_STRING_FULL,
+            sizeof( MBEDTLS_VERSION_STRING_FULL ) );
+}
+
+#endif /* MBEDTLS_VERSION_C */