libreboot is a distribution of coreboot and a payload (GRUB in most mainboard
ROMs), and that step is specific to libreboot's GRUB configuration.
Whether you need to do anything like that depends on your coreboot payload
(and configuration thereof). If you're using coreboot's default payload of
SeaBIOS and you have the grub-pc package (GRUB built for a BIOS) installed in
Trisquel, you should be all set.
(There would be no harm in running those commands anyway, and they would only
need to be run once.)
