MLO(NAND/MMC boot image), is used for all the ks2 platforms.
Enabling it in config.mk so that these images will be automatically
built upon calling make. u-boot-spi.gph is already the build target,
so not including here.
Reported-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>