locking/atomic: Remove linux/atomic.h:atomic_fetch_or()

Since all architectures have this implemented now natively, remove this
dead code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/xtensa/include/asm/atomic.h

@@ -188,8 +188,6 @@ ATOMIC_OPS(sub)
 #undef ATOMIC_OPS
 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
 
-#define atomic_fetch_or atomic_fetch_or
-
 ATOMIC_OPS(and)
 ATOMIC_OPS(or)
 ATOMIC_OPS(xor)