perf tools: Move generic barriers out of perf-sys.h

We will need it for atomic.h, so move it from the ad-hoc tools/perf/
place to a tools/ subset of the kernel arch/ hierarchy.

The parisc stuff was just using the asm-generic/barrier.h, no need to
introduce a tools/arch/parisc/ tree just yet.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-tfas9bs1gje0hfsvhqgrosd6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/include/asm/barrier.h b/tools/include/asm/barrier.h
index c23fff3..ac66ac5 100644
--- a/tools/include/asm/barrier.h
+++ b/tools/include/asm/barrier.h
@@ -22,4 +22,6 @@
 #include "../../arch/ia64/include/asm/barrier.h"
 #elif defined(__xtensa__)
 #include "../../arch/xtensa/include/asm/barrier.h"
+#else
+#include <asm-generic/barrier.h>
 #endif