Add support for Jlink

[jerome-pouiller]

diff --git i/boards/arm/siwg917_brd4338a/board.cmake w/boards/arm/siwg917_brd4338a/board.cmake
index 745dd50f245..de5ac75cd7f 100644
--- i/boards/arm/siwg917_brd4338a/board.cmake
+++ w/boards/arm/siwg917_brd4338a/board.cmake
@@ -2,5 +2,8 @@
 #
 # SPDX-License-Identifier: Apache-2.0

+board_runner_args(jlink "--device=SI917" "--speed=4000")
+include(${ZEPHYR_BASE}/boards/common/jlink.board.cmake)
+
 board_runner_args(silabs_commander "--device=SiWG917M612LGTAA")
 include(${ZEPHYR_BASE}/boards/common/silabs_commander.board.cmake)

JLink must contains JLinkDevices.xml from commander

Then west attach will work. However west flash and west debug do not work yet.