sh: Use generic atomic64_t implementation.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/atomic.h

@@ -85,4 +85,6 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 #define smp_mb__after_atomic_inc()	barrier()
 
 #include <asm-generic/atomic-long.h>
+#include <asm-generic/atomic64.h>
+
 #endif /* __ASM_SH_ATOMIC_H */