Claim on IEEE1275

[Marco Gerards]

Hi,

Some minutes ago I have committed a patch that removes the stack
initialization code.  This seems to work perfectly fine for both the
PegasosII and the newworld mac.  This was required for loading linux
on the PegasosII.  Without this change linux crashed when decompressing
itself.  It's ok for me to restore this code when the problem is
found.  But at the moment this seems like a fine fix.

Only one problem remains for loading linux on the PegasosII.  The
grub_claimmap call fails because the map fails.  I think this is
because the firmware already maps the memory.

Hollis, is the map call really required?  We can better go back to
using grub_ieee1275_claim if it is not.  If it is required, do you
have an idea of how to detect this?

Thanks,
Marco