boards: infineon: cyw920829m2evk_02: set openocd target handle

Openocd target cyw20829 does not define _TARGETNAME which is used by
default by the openocd west runner when using CONFIG_DEBUG_THREAD_INFO.

This is similar to the issue previously addressed for STM32H7:

Link: https://github.com/zephyrproject-rtos/zephyr/issues/45778



Signed-off-by: Hakan Jansson <hakan.jansson@infineon.com>