perf Documentation: Remove Ruplicated docs for powerpc cpu specific events

Listing specific events doesn't actually help us at all here because:
 - these events actually vary between different ppc processors, they
   aren't garunteed to be present.
 - the documentation of the (generic) file contents is now superceded by the
   docs for arbitrary event file contents.

Signed-off-by: Cody P Schafer <dev@codyps.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1412143402-26061-5-git-send-email-sukadev@linux.vnet.ibm.com


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