alpha: convert to asm-generic/hardirq.h

Index: linux-2.6/arch/alpha/include/asm/hardirq.h
===================================================================
@@ -1,17 +1,9 @@
 #ifndef _ALPHA_HARDIRQ_H
 #define _ALPHA_HARDIRQ_H
 
-#include <linux/threads.h>
-#include <linux/cache.h>
-
-
-/* entry.S is sensitive to the offsets of these fields */
-typedef struct {
-	unsigned long __softirq_pending;
-} ____cacheline_aligned irq_cpustat_t;
-
-#include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */
-
 void ack_bad_irq(unsigned int irq);
+#define ack_bad_irq ack_bad_irq
+
+#include <asm-generic/hardirq.h>
 
 #endif /* _ALPHA_HARDIRQ_H */