zephyr: fix include in hello-world app
zephyr: fix include in hello-world app

Update include due to changes in Zephyr. This is related to commit
f1d189c48649f179e6a9fcd71abe90cff82ad6b5.

Signed-off-by: Fabio Utzig <66676b1ceaf93296e098708c09494361103aa635@apache.org>

runtimeco/mcuboot,runtimeco/mcuboot,tamban01/mcuboot,tamban01/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,runtimeco/mcuboot,tamban01/mcuboot,tamban01/mcuboot,ATmobica/mcuboot,ATmobica/mcuboot,utzig/mcuboot,tamban01/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,utzig/mcuboot,utzig/mcuboot,utzig/mcuboot,utzig/mcuboot