Introduce a second phase in the kpatch-build process that creates kpatch
modules or livepatch modules that use the new klp rela sections depending on
the kernel version being worked on. This change uses the two new programs to
either create a patch module that uses dynrelas (create-kpatch-module) or a
patch module that uses klp rela and arch sections + klp symbols marked with the
correct Elf flags (create-klp-module).
For klp patch modules, the --unique flag for ld is needed to prevent
.parainstructions and .altinstructions sections from different objects
from being merged, as arch_klp_init_object_loaded() applies these sections
per-object.
Jessica Yu