Update zephyr to support Greybus

This adds a couple of changes required to build and use greybus (apply dynamic stack patches). This also update west to fetch greybus for zephyr.

Signed-off-by: Alexandre Bailon abailon@baylibre.com

Depends on: https://git.beagleboard.org/beagleconnect/zephyr/greybus-for-zephyr/-/merge_requests/9