sample: inclusive language: whitelist -> allow
sample: inclusive language: whitelist -> allow

Change whitelist->allow to be compatible with sanitycheck in zephyr.

Signed-off-by: Anas Nashif <0d9952ec84ac43c159f6b7e7ed99a9080c00dd6e@intel.com>

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