perf list: Add a --no-desc flag

Add a --no-desc flag to 'perf list' to not print the event descriptions
that were earlier added for JSON events. This may be useful to get a
less crowded listing.

It's still default to print descriptions as that is the more useful
default for most users.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1473978296-20712-9-git-send-email-sukadev@linux.vnet.ibm.com


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