Support for RAID in grub-setup

[Jeroen Dekkers]

Hi all,

I'm a bit behind the schedule I created for SoC (I had some unplanned
things happening the last 2 weeks), but I've just committed the RAID
support for grub-setup and I'm going to work on LVM support very soon.

Grub-setup will ask Linux for the members of the RAID array that is
given as destination device. It will then install on the MBRs of those
devices and embed core.img after MBR. If it can't embed the core image
it will fail, I'm not sure whether we should support reading core.img
from a RAID array...

I let grub-setup put the RAID device directly into the prefix and put
-2 in grub_install_dos_part. I've modified make_install_device() in
init.c to leave the prefix alone when grub_install_dos_part is -2.

Jeroen Dekkers