Use the device's architecture instead of noarch. Because the device
packages should never be built for other architectures, even if all
depends can be built for other arches as well.
This simplifies package building as part of the new build
infrastructure effort.
pmbootstrap has also been changed to output this by default in
aportgen.
* Added linux-postmarketos-allwinner kernel
* Added copy of alpines u-boot package with pine-a64lts support
* Changed postmarketos-mkinitfs to add the plain .dtb file to the boot partition
