boards: st: nucleo_wb07cc: make OpenOCD script compatible with Zephyr

The old OpenOCD script was expecting usage of ST's OpenOCD fork, but
the WB07 is already supported as "bluenrg-lp" in upstream OpenOCD and
the Zephyr fork provided in SDK.

Update the script to work properly with these two versions, instead of
requiring usage of ST's OpenOCD fork and scripts to function properly.

Signed-off-by: Mathieu Choplain <mathieu.choplain@st.com>