[IA64] Increase max physical address for SN platforms

Increase the value for the maximum physical address on SN systems.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/setup.c

@@ -56,7 +56,7 @@
 
 DEFINE_PER_CPU(struct pda_s, pda_percpu);
 
-#define MAX_PHYS_MEMORY		(1UL << 49)	/* 1 TB */
+#define MAX_PHYS_MEMORY		(1UL << IA64_MAX_PHYS_BITS)	/* Max physical address supported */
 
 lboard_t *root_lboard[MAX_COMPACT_NODES];