clocksource: dw_apb: Fix error check

irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
This breaks on platforms that have NO_IRQ != 0.

Cc: <stable@vger.kernel.org>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/dw_apb_timer_of.c

@@ -44,7 +44,7 @@ static void add_clockevent(struct device_node *event_timer)
 	u32 irq, rate;
 
 	irq = irq_of_parse_and_map(event_timer, 0);
-	if (irq == NO_IRQ)
+	if (irq == 0)
 		panic("No IRQ for clock event timer");
 
 	timer_get_base_and_rate(event_timer, &iobase, &rate);