perf list: Display hybrid PMU events with cpu type

perf list: Display hybrid PMU events with cpu type

Add a new option '--cputype' to 'perf list' to display core-only PMU
events or atom-only PMU events.

Each hybrid PMU event has been assigned with a PMU name, this patch
compares the PMU name before listing the result.

For example:

  perf list --cputype atom
  ...
  cache:
    core_reject_l2q.any
         [Counts the number of request that were not accepted into the L2Q because the L2Q is FULL. Unit: cpu_atom]
  ...

The "Unit: cpu_atom" is displayed in the brief description section
to indicate this is an atom event.

Signed-off-by: Jin Yao <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>