board: kontron: disable flash unlock all

board: kontron: disable flash unlock all

Although the status register is protected by the hardware write
protection, there is a hardware jumper to disable that hardware write
protection. Thus if a user would set this jumper any u-boot start would
disable the write protection altogether.

Circumvent that by not disabling the write protection in the first
place.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>