[yocto] GRUB fix for 1.1: Preferred approach for default grub version

[Darren Hart]

When grub2 was merged int oe-core, it became the default (rather than
being explicitly requested by the 64b meta-intel BSPs). This breaks the
live install on 32b systems, like the n450 - installing grub v1.99 with
a grub v1 config.

We have a couple options on how to fix this.

1) Set PREFERRED_PROVIDER_grub="0.97" in all 32b x86 machine configs
2) Set DEFAULT_PREFERENCE="-1" in the grub_1.99.bb recipe which would
   affect all of oe-core.
3) Some alternate approach which would be the equivalent of
   DEFAULT_PREFERENCE, but only for meta-yocto BSPs or the poky
   "distro".

Given the time frame, I'd prefer to agree on the approach before writing
and testing patches. Preferences?

Thanks,

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel