locking,arch,parisc: Fold atomic_ops

locking,arch,parisc: Fold atomic_ops

OK, no LoC saved in this case because sub was defined in terms of add.
Still do it because this also prepares for easy addition of new ops.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linux-parisc@vger.kernel.org
Link: http://lkml.kernel.org/r/20140508135852.659342353@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>