main/unl0kr: add to initramfs-extra

This moves unl0kr and all of its dependencies into the initramfs-extra archive. The initramfs archive's size does not change when FDE support is enabled with unl0kr. As a result, any device (including those with a small boot partition) that can boot pmOS should be able to have unl0kr available in the initramfs environment. However this only addresses size-related issues, other functional problems aren't going to be solved by this change.