CI: add cmsis_6

Added cmsis_6 to the repository in line with the update of Zephyr.

Signed-off-by: TOKITA Hiroshi <[email protected]>

Author: soburi

west.yml

@@ -19,5 +19,6 @@ manifest:
       import:
         name-allowlist:
           - cmsis      # required by the ARM port
+          - cmsis_6    # required by the ARM port
           - hal_nordic # required by the custom_plank board (Nordic based)
           - hal_ti