perf stat: Reorganize output

 - use IPC for the instruction normalization output
 - CPUs for the CPU utilization factor value.
 - print out time elapsed like the other rows
 - tidy up the task-clocks/cpu-clocks printout

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>