arch,avr32: Convert smp_mb__*()

AVR32's mb() implementation is a compiler barrier(), therefore it all
doesn't matter, fully rely on whatever asm-generic/barrier.h
generates.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-8gow97a7mapmnec0pvf729pj@git.kernel.org
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/avr32/include/asm/atomic.h

@@ -183,9 +183,4 @@ static inline int atomic_sub_if_positive(int i, atomic_t *v)
 
 #define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
 
-#define smp_mb__before_atomic_dec()	barrier()
-#define smp_mb__after_atomic_dec()	barrier()
-#define smp_mb__before_atomic_inc()	barrier()
-#define smp_mb__after_atomic_inc()	barrier()
-
 #endif /*  __ASM_AVR32_ATOMIC_H */

arch/avr32/include/asm/bitops.h

@@ -13,12 +13,7 @@
 #endif
 
 #include <asm/byteorder.h>
-
-/*
- * clear_bit() doesn't provide any barrier for the compiler
- */
-#define smp_mb__before_clear_bit()	barrier()
-#define smp_mb__after_clear_bit()	barrier()
+#include <asm/barrier.h>
 
 /*
  * set_bit - Atomically set a bit in memory
@@ -67,7 +62,7 @@ static inline void set_bit(int nr, volatile void * addr)
  *
  * clear_bit() is atomic and may not be reordered.  However, it does
  * not contain a memory barrier, so if it is used for locking purposes,
- * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
+ * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
  * in order to ensure changes are visible on other processors.
  */
 static inline void clear_bit(int nr, volatile void * addr)