mobile always uses role::cache::configuration

We used to setup the backends in role::cache::mobile using
lvs::configuration::lvs_service_ips.  Since we do not have LVS in labs,
that caused a bit of havoc by pointing the backends to a fake IP.

Instead, fill in the lvs_service_ips in the role::cache::configuration
which let us specifiy the proper backends to be used for the beta
cluster.

Change-Id: I19e5ec633a96a942e5c0cb465944eea33547f60d