Remove unused InstanceInfo class.
Remove unused InstanceInfo class.

We no longer use InstanceInfo.

Also removes some unused _map_to_instance_info functions in
various virt drivers.

Change-Id: I02ead10e43426b9ad051970e9e78e970de5b1ac1

Tan0/ironic,SauloAislan/ironic,dims/ironic,openstack/ironic-lib,varunarya10/ironic,faizan-barmawer/elytics,naototty/vagrant-lxc-ironic,debayanray/ironic_backup,bacaldwell/ironic,redhat-openstack/ironic,citrix-openstack-build/ironic,openstack/ironic,faizan-barmawer/ironic-lib,ionutbalutoiu/ironic,rdo-management/ironic,Tehsmash/ironic,naterh/ironic,faizan-barmawer/openstack_ironic,ionutbalutoiu/ironic,pshchelo/ironic,pshchelo/ironic,NaohiroTamura/ironic,devananda/ironic,bacaldwell/ironic,citrix-openstack-build/ironic-lib,dims/ironic,froyobin/ironic,emonty/ironic,NaohiroTamura/ironic,ramineni/myironic,NaohiroTamura/ironic-lib,supermari0/ironic,citrix-openstack-build/ironic,JioCloud/ironic,openstack/ironic,rackerlabs/ironic,naototty/vagrant-lxc-ironic,hpproliant/ironic,SauloAislan/ironic