Provide an explicit configuration option to disable default "unlock all"
of any flash chip which supports locking. It doesn't make sense to
automatically unprotect the entire flash on each u-boot startup if the
block protection bits are actually used.
Traditionally, the unlock was there to be able to write to flash devices
which powered-up with the block protection bits set. Over time this
feature creeped into all flash devices which support locking.
For a more detailed description and discussion see:
https://lore.kernel.org/linux-mtd/20201203162959.29589-8-michael@walle.cc/
Keep things simple in u-boot and just provide a configration option to
disable this behavior which can be set per board.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>