Give error when IMAGE_BOOTLOADER_BOOTSECTOR_OFFSET is not kB-aligned.
Give error when IMAGE_BOOTLOADER_BOOTSECTOR_OFFSET is not kB-aligned.

Changelog: Title

Signed-off-by: Kristian Amlie <505e66ae45028a0596c853559221f0b72c1cee21@mender.io>

bboozzoo/meta-mender,bboozzoo/meta-mender,bboozzoo/meta-mender,bboozzoo/meta-mender