Previously we use a specific integration bridge for neutron ovs agent
which is running in compute node, but this isn't necessary, this
patch is to remove the specific integration bridge for XenSever and
remove the custom integration bridge definition
Depends-On: I675565e1ea6c887d40d7a53f62968c4aa385ecca
Change-Id: If5886e3711765a97f40f20e478f958b988b5a620