dpdk: Add dpdk_service_cores traceThis trace can be used to test the Logical Core analysis[1].[1]https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/200457Signed-off-by: Arnaud Fiorini <fiorini.arnaud@gmail.com>Change-Id: I0b011d72447c2b9f665bf5e858b233dbb12e4c4fReviewed-on: https://git.eclipse.org/r/c/tracecompass/tracecompass-test-traces/+/201469Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>Tested-by: Matthew Khouzam <matthew.khouzam@ericsson.com>Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>