This patch detects the existence of an uncached physical AMO address setup
by EFI's XPBOOT (SGI) and converts it to an uncached virtual AMO address.
Depends on a patch submitted on 23 March 2005 with the subject of:
    [PATCH 2/3] SGI Altix cross partition functionality (2nd revision)
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>