Install uboot files to KERNEL_BUILD_DIR instead of BIN_DIR to fix
ImageBuilder. Similar fixes are necessary for many (all?) other uboot
targets.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Backport of r46605
git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@48835 3c298f89-4303-0410-b956-a3cf2f4a3e73