Remove also EFI version of BootLoader Specification dirs. This will:
- really force to re-generate initramfs during installation, after all
relevant configs are updated; previously, dracut (called by anaconda
through kernel-install) refuse to update already existing
/boot/efi/.../initrd file.
- save some precious space in /boot/efi
FixesQubesOS/qubes-issues#3234
The specification doesn't cover how to boot Xen (or any other multiboot
binary), but the sole presence of such directory changes dracut default
path. So get rid of that directory.