arm: mvebu: turris_mox: enable options for Turris network boot

Enable configuration options to support Turris network boot. This
includes FIT support and some crypto commands.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>