- Increase the test coverage of supported platforms.
- Fix test_flash_area_check_int_sha256 for platforms with
flash program size >32. Increase the supported flash program size
to 512 (maximum supported by Zephyr platforms now).
- Fix test_flash_area_get_sectors test for platforms
with maximum number of sectors per image slot >256.
Increase the support value to 1024.
- Fix possible stack size overflow.
Signed-off-by: Andrej Butok <andrey.butok@nxp.com>