machine: Add SMP Sockets in CpuTopology

Store the  smp sockets in CpuTopology. The socket information required to
build the apic id in EPYC mode. Right now socket information is not passed
to down when decoding the apic id. Add the socket information here.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <158396718647.58170.2278448323151215741.stgit@naples-babu.amd.com>