Fix header file include guard names

Make the include guards consistent by renaming them systematically according
to the naming conventions below

For the public header files (in the 'include/openssl' directory), the guard
names try to match the path specified in the include directives, with
all letters converted to upper case and '/' and '.' replaced by '_'. For the
private header files files, an extra 'OSSL_' is added as prefix.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9333)
diff --git a/include/crypto/sm2.h b/include/crypto/sm2.h
index dad70e6..4a65ce4 100644
--- a/include/crypto/sm2.h
+++ b/include/crypto/sm2.h
@@ -9,8 +9,8 @@
  * https://www.openssl.org/source/license.html
  */
 
-#ifndef HEADER_SM2_H
-# define HEADER_SM2_H
+#ifndef OSSL_CRYPTO_SM2_H
+# define OSSL_CRYPTO_SM2_H
 # include <openssl/opensslconf.h>
 
 # ifndef OPENSSL_NO_SM2