Use both load_config() and load_config_prefix() functions when
dynamically loading a module from the extras directory - if the config
section name has parameters in it then use load_config_prefix().
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The print cooling fan and printer heater_fan are independent modules
that can reside in the extras directory.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>