Add patches to support population IPL sections using BootLoaderSpec files
instead of having them defined in the zipl.conf file. This allows to have
a static zipl.conf file, and update the boot entries by just dropping BLS
fragments files in a directory.
In this configuration the grubby tool isn't used, and instead all needed
tasks (copy kernel, generate an initramfs, copy BLS configs, etc) should
be made by kernel-install scripts.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>