make: add capability to check config for `test-with-config`
make: add capability to check config for `test-with-config`

kaspar030/RIOT,miri64/RIOT,kYc0o/RIOT,miri64/RIOT,ant9000/RIOT,OlegHahm/RIOT,kYc0o/RIOT,miri64/RIOT,authmillenon/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,authmillenon/RIOT,miri64/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,jasonatran/RIOT,ant9000/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,miri64/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,kYc0o/RIOT,OlegHahm/RIOT,kaspar030/RIOT,ant9000/RIOT,jasonatran/RIOT,jasonatran/RIOT,kaspar030/RIOT,kYc0o/RIOT,OlegHahm/RIOT,ant9000/RIOT,authmillenon/RIOT,jasonatran/RIOT,kaspar030/RIOT,ant9000/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,OlegHahm/RIOT