[PATCH] interrupt.h needs kernel.h

<linux/interrupt.h> uses barrier() but does not include <linux/kernel.h>.

include/linux/interrupt.h

@@ -3,6 +3,7 @@
 #define _LINUX_INTERRUPT_H
 
 #include <linux/config.h>
+#include <linux/kernel.h>
 #include <linux/linkage.h>
 #include <linux/bitops.h>
 #include <linux/preempt.h>