AP_Scripting: allow AP_SCRIPTING_ENABLED to come from hwdef files

libraries/AP_Scripting/AP_Scripting_helpers.cpp

@@ -1,3 +1,7 @@
+#include "AP_Scripting_config.h"
+
+#if AP_SCRIPTING_ENABLED
+
 #include "AP_Scripting_helpers.h"
 #include <AP_Scripting/lua_generated_bindings.h>
 
@@ -192,3 +196,5 @@ bool Parameter::set_default(float value)
     // not a supported type
     return false;
 }
+
+#endif  // AP_SCRIPTING_ENABLED