irqchip/keystone: Fix typo "sporious" -> "spurious"

Trivial fix to typo in dev_warn message.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lkml.kernel.org/r/20160901104454.26092-1-colin.king@canonical.comSigned-off-by: Jason Cooper <jason@lakedaemon.net>

drivers/irqchip/irq-keystone.c

@@ -109,7 +109,7 @@ static void keystone_irq_handler(struct irq_desc *desc)
 			dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
 				src, virq);
 			if (!virq)
-				dev_warn(kirq->dev, "sporious irq detected hwirq %d, virq %d\n",
+				dev_warn(kirq->dev, "spurious irq detected hwirq %d, virq %d\n",
 					 src, virq);
 			generic_handle_irq(virq);
 		}