telemetry: keep threads separate from data plane

telemetry: keep threads separate from data plane

The threads for listening on the telemetry sockets are control threads
and should be separated from those on the data plane. Since telemetry
cannot use the rte_ctrl_thread_create() API, as it does not depend on
EAL, we pass the ctrl thread cpu_set to telemetry init and use it
directly to ensure that telemetry cannot interfere with the data plane
threads.

Signed-off-by: Ciara Power <ciara.power@intel.com>
Acked-by: Kevin Laatz <kevin.laatz@intel.com>