For software RAID in UEFI mode, we create ESPs on all holder disks
and copy the bootloader there. Since there is no mechanism to keep
the ESPs in sync, e.g. on kernel upgrades or when kernel parameters
are updated, the ESPs will get out of sync eventually. This may lead
to a situation where a node boots with outdated parameters or does
not have any of the installed kernels in the boot menu anymore.
This change proposes to RAID the ESPs. While the UEFI firmware will
find an ESP partition (one leg of the mirror), the node will see
an md device and all subsequent updates will go to all member disks.
Also, remove the source ESP after copying in order to avoid mount
confusion (same UUID!).
(cherry picked from commit c2d04dc156)