synch with upstream a513b8e6

    Synchronized up to:
    https://github.com/mcu-tools/mcuboot/commit/a513b8e66875035ae2bfe7934caead852b410847



    - fix build issue caused by that CONFIG_LOG_MINIMAL was replaced by CONFIG_LOG_MODE_MINIMAL
    - imgtool: fix validation with protected TLVs

    Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>