vdsm: Hardware information about POWER hosts

This introduces information about the hardware of IBM POWER hosts.
In these machines the dmidecode cannot be used.

This patch also creates a module used by functions that need to
retrieve information about PPC64 hosts. It includes a function to
get hardware platform information about the host.

Change-Id: Ice513b9386273a44146852944741578023c1e17a
Signed-off-by: Vitor de Lima <vitor.lima@eldorado.org.br>
Reviewed-on: http://gerrit.ovirt.org/19395
Reviewed-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>
Tested-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>