Explicitly define if ipxe is enabled or not
Explicitly define if ipxe is enabled or not

This is implicitly relying on the default iPXE setting in devstack.
Explicitly set it so we can possibly change the default.

Change-Id: I0d434f5240f4ab8e2cceb50e934014196e82812e

openstack-infra/project-config,dongwenjuan/project-config,Tesora/tesora-project-config,dongwenjuan/project-config,Tesora/tesora-project-config,openstack-infra/project-config