nios2: Remove write-only struct member from nios2_timer

The irq member of struct nios2_timer is only written to but
never read, thus it can be removed.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Ley Foon Tan <lftan@altera.com>

arch/nios2/kernel/time.c

@@ -33,7 +33,6 @@
 struct nios2_timer {
 	void __iomem *base;
 	unsigned long freq;
-	int irq;
 };
 
 struct nios2_clockevent_dev {
@@ -232,7 +231,6 @@ static __init void nios2_clockevent_init(struct device_node *timer)
 		panic("Unable to parse timer irq\n");
 
 	nios2_ce.timer.base = iobase;
-	nios2_ce.timer.irq = irq;
 	nios2_ce.timer.freq = freq;
 
 	nios2_ce.ced.cpumask = cpumask_of(0);