Use sysfs to gather host topology, in place of

Use sysfs to gather host topology, in place of

 /proc/cpuinfo

Libvirt at present depends on /proc/cpuinfo to gather host
details such as CPUs, cores, threads, etc. This is an architecture-
dependent approach. An alternative is to use 'Sysfs', which provides
a platform-agnostic interface to parse host CPU topology.

Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>