The TI CC3220 LaunchPad evaluation board does come with an on board debugger (XDS110) which drives the debug signals by default. In order to be able to connect with a J-Link to the CC3220SF device, the jumpers as shown on image below needs to be removed in order to isolate the on board debugger. The J-Link needs to be connected through the 9-pin Cortex-M connector (JTAG_IN).
If powering the board via the top USB connector, leave all four power supply jumpers connected(J21/J20/J19/J17)
If powering the board via an external power supply, remove all four power supply jumpers (J21/J20/J19/J17)