[IA64] Fix build breakage - sn_force_interrupt_flag: undefined

Latest irq changes removed the need for this forcing flag, and the
definition - but missed the code that allowed it to be tweaked via
/proc.  Delete accessor functions too.

Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/sn2/sn_proc_fs.c b/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
index c76d8dc..7aab87f 100644
--- a/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
+++ b/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
@@ -45,38 +45,6 @@
 	return single_open(file, licenseID_show, NULL);
 }
 
-/*
- * Enable forced interrupt by default.
- * When set, the sn interrupt handler writes the force interrupt register on
- * the bridge chip.  The hardware will then send an interrupt message if the
- * interrupt line is active.  This mimics a level sensitive interrupt.
- */
-extern int sn_force_interrupt_flag;
-
-static int sn_force_interrupt_show(struct seq_file *s, void *p)
-{
-	seq_printf(s, "Force interrupt is %s\n",
-		sn_force_interrupt_flag ? "enabled" : "disabled");
-	return 0;
-}
-
-static ssize_t sn_force_interrupt_write_proc(struct file *file,
-		const char __user *buffer, size_t count, loff_t *data)
-{
-	char val;
-
-	if (copy_from_user(&val, buffer, 1))
-		return -EFAULT;
-
-	sn_force_interrupt_flag = (val == '0') ? 0 : 1;
-	return count;
-}
-
-static int sn_force_interrupt_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, sn_force_interrupt_show, NULL);
-}
-
 static int coherence_id_show(struct seq_file *s, void *p)
 {
 	seq_printf(s, "%d\n", partition_coherence_id());
@@ -114,14 +82,6 @@
 	.release	= single_release,
 };
 
-static const struct file_operations proc_sn_force_intr_fops = {
-	.open		= sn_force_interrupt_open,
-	.read		= seq_read,
-	.write		= sn_force_interrupt_write_proc,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static const struct file_operations proc_coherence_id_fops = {
 	.open		= coherence_id_open,
 	.read		= seq_read,
@@ -149,8 +109,6 @@
 	proc_create("system_serial_number", 0444, sgi_proc_dir,
 		    &proc_system_sn_fops);
 	proc_create("licenseID", 0444, sgi_proc_dir, &proc_license_id_fops);
-	proc_create("sn_force_interrupt", 0644, sgi_proc_dir,
-		    &proc_sn_force_intr_fops);
 	proc_create("coherence_id", 0444, sgi_proc_dir,
 		    &proc_coherence_id_fops);
 	proc_create("sn_topology", 0444, sgi_proc_dir, &proc_sn_topo_fops);