Update SM2 Extensions

Arrange source files

tests/sm2_elgamaltest.c

@@ -0,0 +1,22 @@
+/*
+ *  Copyright 2014-2022 The GmSSL Project. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the License); you may
+ *  not use this file except in compliance with the License.
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <gmssl/sm2.h>
+#include <gmssl/sm2_elgamal.h>
+#include <gmssl/error.h>
+
+
+int main(void)
+{
+	return 0;
+}