The datasheets for all STM32C0xx devices report that only SWD is supported. No TDI/TDO pin is present. Drop swj support. Add swd transport. Remove swd transport from the associated board files. Change-Id: If6e630858aa64fbb3938a520604748f3f0ff7356 Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Reviewed-on: https://review.openocd.org/c/openocd/+/9423 Reviewed-by: Tomas Vanek <vanekt@fbl.cz> Reviewed-by: Ahmed Haoues <ahmed.haoues@st.com> Tested-by: jenkins