Reorganize public header files (part 2)

Add an <openssl/ossl_typ.h> compatibility header.

Reviewed-by: Richard Levitte <[email protected]>
(Merged from openssl#9333)

Author: mspncp

include/openssl/ossl_typ.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+ * The original <openssl/ossl_typ.h> was renamed to <openssl/types.h>
+ *
+ * This header file only exists for compatibility reasons with older
+ * applications which #include <openssl/ossl_typ.h>.
+ */
+# include <openssl/types.h>