doc: Fix typo

docs/tg/xilinx.md

@@ -63,7 +63,7 @@ For analysis and debugging purposes, integrated logic analyzer (ILA) probes may
 To establish a debug bridge over JTAG, ensure the target is in a debuggable state (for example by resetting into the idle boot mode 0) and launch OpenOCD with:
 
 ```
-openocd -f util/openocd.<board_or_adapter>.cfg
+openocd -f util/openocd.<board_or_adapter>.tcl
 ```
 
 If multiple JTAG adapters are connected to your debugging machine, you may have to extend the script to specify desired adapter's serial number.