Move devstack emulators configs under /etc/ironic
Move devstack emulators configs under /etc/ironic

Moves the config files of virtualpdu, virtualbmc and sushy-tools
emulators under $IRONIC_CONF_DIR (defaulting to /etc/ironic)
to have the configs in post-mortem dumps.

Depends-On: https://review.openstack.org/#/c/651202/
Change-Id: Iea895c157a199d257b751b41a127849d43ad139f

openstack/ironic,openstack/ironic