Deprecate ENGINE_cleanup() and make it a no-op

ENGINE_cleanup() should not be called expicitly - we should leave
auto-deinit to clean this up instead.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

crypto/include/internal/engine.h

@@ -62,3 +62,4 @@ void engine_load_padlock_internal(void);
 void engine_load_capi_internal(void);
 void engine_load_dasync_internal(void);
 void engine_load_afalg_internal(void);
+void engine_cleanup_intern(void);