Fix providing port id when creating PT

We do not allow providing the port name, only the port-id.

The current logic to obtain the port-id from port-name
was causing this to break and is being removed.

Translation from port-name to port-id will require
making a call on the neutron client which is currently
not supported.

Change-Id: Iad5fc245aabf3d076a27890ee7155607e1c1ecfb
Closes-bug: 1392158