Drop old deprecations

This module has been used for a while, it's time to drop deprecations.

* drop cloud::compute::controller, replaced by cloud::compute::{api,scheduler,...}
* drop cloud::image, replaced by cloud::image::{api,registry}
* drop cloud::telemetry::server, replaced by cloud::telemetry::{api,alarm,...}
* hypervisor: delete has_ceph parameter
* hypervisor: drop backward compatibility for spice params
* loadbalancer: drop two old parameters for keepalived
* loadbalancer: drop useless comments
* volume: delete cloud::volume::controller (replaced by api,scheduler)
* volume: only keep multi-backend support

Change-Id: I7376fe0f3bfa3eb00589eb3b7a4532236765e560
(cherry picked from commit 8e523680c960a15c5e8f3abb53abb905fab494d7)