Add audit middleware options to ironic.conf

Ironic supports enabling the audit middleware. This change adds
the option for the middleware to the ironic.conf file generated by
oslo-config-generator.

Depends-on: https://review.opendev.org/804316
Change-Id: Ic7adb755f47ea65fe975dfbc7cca905a376d728e

tools/config/ironic-config-generator.conf

@@ -23,4 +23,5 @@ namespace = oslo.service.service
 namespace = oslo.service.periodic_task
 namespace = oslo.service.sslutils
 namespace = osprofiler
+namespace = keystonemiddleware.audit
 namespace = keystonemiddleware.auth_token