perf script: Fix event ordering settings to work with older kernels

If we don't use .ordering_requires_timestamps we'll end up trying to order
events with no timestamps when running on older kernels.

Problem introduced in eac23d1c

.

After the last three fixes, perf scripting is back working, tested with
new perf userspace on old and new (with sample_id_all) kernels.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Torok Edwin <edwintorok@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>