cmd: mvebu/bubt: Better guess default MVEBU_*_BOOT option

For 32-bit Armada boards which use SPL we can determinate boot device from
existing MVEBU_SPL_BOOT_DEVICE_* option. For all other boards (e.g. 64-bit
Armada) default option still needs to be set manually.

Signed-off-by: Pali Rohár <pali@kernel.org>
1 file changed