uboot: install packages for U-Boot configuration prior kernel

On Arm64 post-install of initramfs do not call zz-u-boot-menu from u-boot-menupackage if it is installed in the same time with the kernel. In case if it is installed before the kernel in separate action -- it works well and produces bootable configuration.

Signed-off-by: Denis Pynkin denis.pynkin@collabora.com