Revert moving SHA512 flag outside ED25519 build

Author: danielinux

include/user_settings.h

@@ -70,13 +70,13 @@ extern int tolower(int c);
 #endif
 
 /* ED25519 and SHA512 */
-#define WOLFSSL_SHA512
 #ifdef WOLFBOOT_SIGN_ED25519
 #   define HAVE_ED25519
 #   define ED25519_SMALL
 #   define NO_ED25519_SIGN
 #   define NO_ED25519_EXPORT
 #   define USE_SLOW_SHA512
+#   define WOLFSSL_SHA512
 #endif
 
 /* ED448 and SHA3/SHAKE256 */