[kernel-xen] adding pv_grub2

[Glenn Enright]

Trying to guage the communinty interest in using pv_grub2, vs pv_grub. 
Please sing out of you want or object to this feature or if you have any 
thoughts about how it should be included.

 From the bug report at http://xen.crc.id.au/bugs/view.php?id=73

It looks like upstream may be deprecating pv_grub in favour of pv_grub2.

http://www.gossamer-threads.com/lists/xen/devel/417646

It would be good to have that included in the xen build alongside 
pv_grub so we have the option to migrate gracefully before pv_grub stops 
being supported any more.

Regards
--Glenn