This patch improves the panic/die notifiers in this driver by
making use of a passed "id" instead of comparing pointer
address; also, it removes an useless prototype declaration
and unnecessary header inclusion.

This is part of a panic notifiers refactor - this notifier in
the future will be moved to a new list, that encompass the
information notifiers only.

--- a/drivers/bus/brcmstb_gisb.c
+++ b/drivers/bus/brcmstb_gisb.c

@@ -347,25 +346,14 @@ static irqreturn_t brcmstb_gisb_bp_handler(int irq, void *dev_id)
 /*
  * Dump out gisb errors on die or panic.
  */
-static int dump_gisb_error(struct notifier_block *self, unsigned long v,
-			   void *p);
-
-static struct notifier_block gisb_die_notifier = {
-	.notifier_call = dump_gisb_error,
-};
-
-static struct notifier_block gisb_panic_notifier = {
-	.notifier_call = dump_gisb_error,
-};
-
 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
 			   void *p)
 {
 	struct brcmstb_gisb_arb_device *gdev;
-	const char *reason = "panic";
+	const char *reason = "die";
 
-	if (self == &gisb_die_notifier)
-		reason = "die";
+	if (v == PANIC_NOTIFIER)
+		reason = "panic";