arch,parisc: Convert smp_mb__*()

arch,parisc: Convert smp_mb__*()

parisc fully relies on asm-generic/barrier.h, therefore its smp_mb()
is barrier and the default implementation suffices.

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-mxs4aubiyesi79v8xx53093q@git.kernel.org
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>