core: Add ppc64 CPUs to the CPU list

* This introduces some ppc64 CPUs to the ServerCPUList.
* The ClusterEmulatedMachines configuration value was changed to
  include the "pseries" emulated machine.
* The ArchitectureType enum (and its correspoding REST API type)
  was changed to include the ppc64 architecture
* The CpuFlagsManagerHandler class was modified to handle the
  IBM processor vendor

Change-Id: Id56ef93cd377bdadc10db008618ab4bbb8ed7170
Signed-off-by: Vitor de Lima <vitor.lima@eldorado.org.br>
Signed-off-by: Gustavo Pedrosa <gustavo.pedrosa@eldorado.org.br>