Add a 16MiB reserved partition to arm64 recipes (#1078871)
Some UEFI and non-UEFI arm64 platforms require to reserve up to the first 16MiB of the disk for the U-Boot boot loader.
Proposed implementation:
- replace recipes-arm64 and recipes-arm64-efi symlinks with real directories
- add a 18MB unused partition at the beginning of the recipes
Closes: #1078871