perf report: Introduce --socket-filter option

Introduce --socket-filter option for 'perf report' to only show entries
for a processor socket that match this filter.

  $ perf report --socket-filter 1 --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 752  of event 'cycles'
  # Event count (approx.): 350995599
  # Processor Socket: 1
  #
  # Overhead  Command    Shared Object     Symbol
  # ........  .........  ................  .................................
  #
      97.02%  test       test              [.] plusB_c
       0.97%  test       test              [.] plusA_c
       0.23%  swapper    [kernel.vmlinux]  [k] acpi_idle_do_entry
       0.09%  rcu_sched  [kernel.vmlinux]  [k] dyntick_save_progress_counter
       0.01%  swapper    [kernel.vmlinux]  [k] task_waking_fair
       0.00%  swapper    [kernel.vmlinux]  [k] run_timer_softirq

Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1441377946-44429-3-git-send-email-kan.liang@intel.com


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