zephyr: flash HAL requires flash_write_protection_set() calls
zephyr: flash HAL requires flash_write_protection_set() calls

In Zephyr there is a flash HAL function: flash_write_protection_set()
which for many SoCs is a stubbed function with no functionality,
but for others performs the unlock / lock procedures required before
writing to flash.

We need to add this function to our flash_area_write() wrapper
to support the hardware that requires it.

This fixes mcuboot flash writing for the nRF5x SoCs.

Signed-off-by: Michael Scott <087571639a1dbb4ff1803c64e3643475ba482686@linaro.org>

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