AP_Scripting: allow AP_SCRIPTING_ENABLED to come from hwdef files

libraries/AP_Scripting/lua_bindings.cpp

@@ -1,3 +1,7 @@
+#include "AP_Scripting_config.h"
+
+#if AP_SCRIPTING_ENABLED
+
 #include <AP_Common/AP_Common.h>
 #include <AP_HAL/HAL.h>
 #include <AP_Logger/AP_Logger.h>
@@ -700,3 +704,5 @@ int lua_get_current_ref()
     auto *scripting = AP::scripting();
     return scripting->get_current_ref();
 }
+
+#endif  // AP_SCRIPTING_ENABLED