Add support of server name extension to server side

Change-Id: Iccf5017e306ba6ead2e1026a29f397ead084cc4d
Signed-off-by: XiaokangQian <xiaokang.qian@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 9912d6c..f0f4465 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2270,4 +2270,10 @@
 int mbedtls_ssl_write_sig_alg_ext( mbedtls_ssl_context *ssl, unsigned char *buf,
                                    const unsigned char *end, size_t *out_len );
 
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+int mbedtls_ssl_parse_servername_ext( mbedtls_ssl_context *ssl,
+                                      const unsigned char *buf,
+                                      const unsigned char *end );
+#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
+
 #endif /* ssl_misc.h */