[u-boot/omap]: use a single package to build MLO/u-boot for all omap boards

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38626 3c298f89-4303-0410-b956-a3cf2f4a3e73