Input: wm97xx - use disable_irq_nosync() for Mainstone

This should make no practical difference since the Mainstone can't be
SMP but it is more correct.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/mainstone-wm97xx.c

@@ -245,7 +245,7 @@ static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 	if (enable)
 		enable_irq(wm->pen_irq);
 	else
-		disable_irq(wm->pen_irq);
+		disable_irq_nosync(wm->pen_irq);
 }
 
 static struct wm97xx_mach_ops mainstone_mach_ops = {