Merge: synchronized up to 1eedec3e

Synch up to upstream:
https://github.com/mcu-tools/mcuboot/commit/1eedec3e7936f74872aca43f3962246e7abe6439

- fixed the build issue caused by removal of CONFIG_SYSTEM_CLOCK_DISABLE property (within https://github.com/zephyrproject-rtos/zephyr/pull/37435

)
- always call sys_clock_disable() in main since the empty sys_clock_disable() callback is provided if the platform doesn't support system clock disable capability.
- bootutil: Close flash_area after failure to read swap status information
- fixed status offset calculation in case of scratch area
- fixed include path for reboot.h header.

Merged using GitHub web gui

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