tests: functional tests for QMP command set-numa-node

 * start QEMU with 2 unmapped cpus,
 * while in preconfig state
    * add 2 numa nodes
    * assign cpus to them
 * exit preconfig and in running state check that cpus
   are mapped correctly.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1526556607-268163-1-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>