[IA64] Cleanup use of various #defines related to nodes

Some of the SN code & #defines related to compact nodes & IO discovery
have gotten stale over the years. This patch attempts to clean them up.
Some of the various SN MAX_xxx #defines were also unclear & misused.

The primary changes are:

	- use MAX_NUMNODES. This is the generic linux #define for the number
	  of nodes that are known to the generic kernel. Arrays & loops
	  for constructs that are 1:1 with linux-defined nodes should
	  use the linux #define - not an SN equivalent.

	- use MAX_COMPACT_NODES for MAX_NUMNODES + NUM_TIOS. This is the
	  number of nodes in the SSI system. Compact nodes are a hack to
	  get around the IA64 architectural limit of 256 nodes. Large SGI
	  systems have more than 256 nodes. When we upgrade to ACPI3.0,
	  I _hope_ that all nodes will be real nodes that are known to
	  the generic kernel. That will allow us to delete the notion
	  of "compact nodes".

	- add MAX_NUMALINK_NODES for the total number of nodes that
	  are in the numalink domain - all partitions.

	- simplified (understandable) scan_for_ionodes()

	- small amount of cleanup related to cnodes

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/drivers/char/snsc.c b/drivers/char/snsc.c
index 261a41b..a025a89 100644
--- a/drivers/char/snsc.c
+++ b/drivers/char/snsc.c
@@ -377,7 +377,7 @@
 	dev_t first_dev, dev;
 	nasid_t event_nasid = ia64_sn_get_console_nasid();
 
-	if (alloc_chrdev_region(&first_dev, 0, numionodes,
+	if (alloc_chrdev_region(&first_dev, 0, num_cnodes,
 				SYSCTL_BASENAME) < 0) {
 		printk("%s: failed to register SN system controller device\n",
 		       __FUNCTION__);
@@ -385,7 +385,7 @@
 	}
 	snsc_class = class_create(THIS_MODULE, SYSCTL_BASENAME);
 
-	for (cnode = 0; cnode < numionodes; cnode++) {
+	for (cnode = 0; cnode < num_cnodes; cnode++) {
 			geoid = cnodeid_get_geoid(cnode);
 			devnamep = devname;
 			format_module_id(devnamep, geo_module(geoid),