This patch removes the deprecated DHCP provider method
``update_port_address``. For users who created their own network
interfaces or DHCP providers the logic should be moved to a custom
network interface's ``port_changed`` and ``portgroup_changed``
methods. The following methods should be implemented by custom
network interfaces:
* ``vif_list``: List attached VIF IDs for a node.
* ``vif_attach``: Attach a virtual network interface to a node.
* ``vif_detach``: Detach a virtual network interface from a node.
* ``port_changed``: Handle any actions required when a port
changes.
* ``portgroup_changed``: Handle any actions required when a
port group changes.
* ``get_current_vif``: Return VIF ID attached to port or port group
object.removes deprecated by [0] DHCP provider update_port_address().
[0] 9088891ce72081684761e5cf54d3b3eabab0ca37
Change-Id: I887f31937c576ff8933e7c1454e0b2cb0962e340