Make kFreeBSD code more generic to support ext2fs as root, ufs as
a separate module and maybe other interesting combinations.
* util/grub.d/10_kfreebsd.in (load_kfreebsd_module): New function.
(kfreebsd_entry): Use load_kfreebsd_module() to load modules.
(kfreebsd_entry): Add generic filesystem module load routine.
Map GRUB `ext2' to kFreeBSD `ext2fs'.