ARM: OMAP1: Fix compile for voiceblue

Fix compile for voiceblue
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap1/board-voiceblue.c

@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/notifier.h>