OpenSDA does not support SWO.
You need an external debug probe which is capable dealing with SWO, e.g. see ARM SWO Performance Counters | MCU on Eclipse
See as well:
I hope this helps
No, you cannot use an external Kinetis as debugger to take advantage of the SWO pin, as that external Kinetis boards would run OpenSDA. As pointed out below: it is not possible to use SWO with OpenSDA because the OpenSDA firmware does not support SWO. The hardware (debug connector) would support it, but not the OpenSDA.
So: you need an external debug probe capable for SWO, either a SEGGER, a P&E or a LPCLink2 probe (as shown in above article).
You don't have to do anything in your application/firmware: the probe firmware will handle everything.