Add support to the port binding extension for the NVP plugin.

Also, this patch removes the non-serializable object for
port profile. This went undetected for quite some time.

Implements blueprint nvp-port-binding-extension

Change-Id: I380570f08e92f75d6431dcda6fac2a770887bb48
Merge "Add support to the port binding extension for the NVP plugin."