As explained in [0], we can add a hook script that will be called after
update-initramfs did its job (and thus, a new initrd has been created).
We can use this to automatically sync the ESPs using 'pve-efiboot-tool
refresh', if update-initramfs was called manually (on kernel upgrade we
already have a hook that does this).
[0]: https://kernel-team.pages.debian.net/kernel-handbook/ch-update-hooks.html
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
