[IA64-SGI] Make number of TIO nodes configurable

Make the limit for the number of TIO nodes a function of the number
of C/M nodes in the system instead of a hardcoded constant.  The
number of TIO nodes should be the same as the number of C/M nodes.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>