[IA64-SGI] Shub2 BTE address fix

After converting the cpu physical address to shub2 physical
addressing, the address was run through TO_PHYS() which
clobbered a high node offset bit causing the BTE to fail
on shub2 nodes with large memory.  This fix corrects
that problem.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>