ns9xxx: check for irq lockups

When I copy-adapted handle_level_irq I skipped note_interrupt because
I considered it unimportant.  If I had understand its importance I would
have saved myself some ours of debugging.
Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

arch/arm/mach-ns9xxx/irq.c

@@ -78,6 +78,11 @@ void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
 
 	action_ret = handle_IRQ_event(irq, action);
 
+	/* XXX: There is no direct way to access noirqdebug, so check
+	 * unconditionally for spurious irqs...
+	 * Maybe this function should go to kernel/irq/chip.c? */
+	note_interrupt(irq, desc, action_ret);
+
 	spin_lock(&desc->lock);
 	desc->status &= ~IRQ_INPROGRESS;