perf script: Add period data column

Adding period data column to be displayed in perf script.  It's possible
to get period values using -f option, like:

  $ perf script -f comm,tid,time,period,ip,sym,dso
          :26019 26019 52414.329088:       3707  ffffffff8105443a native_write_msr_safe ([kernel.kallsyms])
          :26019 26019 52414.329088:         44  ffffffff8105443a native_write_msr_safe ([kernel.kallsyms])
          :26019 26019 52414.329093:       1987  ffffffff8105443a native_write_msr_safe ([kernel.kallsyms])
          :26019 26019 52414.329093:          6  ffffffff8105443a native_write_msr_safe ([kernel.kallsyms])
              ls 26019 52414.329442:     537558        3407c0639c _dl_map_object_from_fd (/usr/lib64/ld-2.17.so)
              ls 26019 52414.329442:       2099        3407c0639c _dl_map_object_from_fd (/usr/lib64/ld-2.17.so)
              ls 26019 52414.330181:    1242100        34080917bb get_next_seq (/usr/lib64/libc-2.17.so)
              ls 26019 52414.330181:       3774        34080917bb get_next_seq (/usr/lib64/libc-2.17.so)
              ls 26019 52414.331427:    1083662  ffffffff810c7dc2 update_curr ([kernel.kallsyms])
              ls 26019 52414.331427:        360  ffffffff810c7dc2 update_curr ([kernel.kallsyms])

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: "Jen-Cheng(Tommy) Huang" <tommy24@gatech.edu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jen-Cheng(Tommy) Huang <tommy24@gatech.edu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1408977943-16594-9-git-send-email-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>