Clean up unneeded deprecated_group
Clean up unneeded deprecated_group

Config generator is changed to use the deprecated opts' group
instead of just 'DEFAULT', so no need to specify the deprecated
group if it's not changed.

Change-Id: I88108e726df015e66b0b9f64762311de2ed4a949

NaohiroTamura/ironic,devananda/ironic,openstack/ironic,bacaldwell/ironic,SauloAislan/ironic,ionutbalutoiu/ironic,pshchelo/ironic,NaohiroTamura/ironic,SauloAislan/ironic,bacaldwell/ironic,ionutbalutoiu/ironic,dims/ironic,pshchelo/ironic,openstack/ironic,dims/ironic