configs: ks2: move CMD_NAND to defconfigs

NAND is not yet enabled on all Keystone2 platforms. So enabled
CMD_NAND in the respective defconfigs only if available.

Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
4 files changed