[ARM] Add asm/irq.h include - required for NR_IRQS

include/asm-arm/hardirq.h

@@ -4,6 +4,7 @@
 #include <linux/config.h>
 #include <linux/cache.h>
 #include <linux/threads.h>
+#include <asm/irq.h>
 
 typedef struct {
 	unsigned int __softirq_pending;