perf evlist: Be more specific on -F/--freq
perf evlist: Be more specific on -F/--freq

Currently perf evlist -F shows the number as if it's always sampling
frequency.  But we now support per-event freq/period settings.  So it'd
better to show more detailed info whether it's freq or period.

  $ perf record -e 'cpu/config=1/,cpu/config=2,period=300000/' sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.017 MB perf.data ]

  $ perf evlist -F
  cpu/config=1/: sample_freq=4000
  cpu/config=2,period=300000/: sample_period=300000

Signed-off-by: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org>
Acked-by: Jiri Olsa <2c6594f608aa3d41e98d48846a6328831f7084ad@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>
Cc: David Ahern <b80c1600f604d3b0d768f26f90a76757e76005dd@gmail.com>
Cc: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Link: http://lkml.kernel.org/r/1439102724-14079-2-git-send-email-5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs