device property: export set_secondary_fwnode() to modules
Some drivers when compiled as modules may need to set secondary firmware node.
Export set_secondary_fwnode() to make it possible without code duplication.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>