perf vendor events: Add power8 PMU events

Add mapfile.csv and power8.json files for the Power8 processor.

Changelog[v3]
	- [Namhyung Kim] Remove text from PublicDescription fields if it is
          identical to or prefix of BriefDescription.

Changelog[v2]
	- [Andi Kleen] Replace the vendor-family-model,version fields with
	  cpuid,version fields (to simplify mapfile)
	- Reuse the JSON files when possible (i.e multiple cpuids can refer
	  to the same JSON file) - so drop the 004d0100.json and use
	  power8.json in multiple entries in mapfile.
	- Add few more Power8 PVRs to mapfile

Changelog[v21]
	- Group events into per topic per cpu model.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
CC: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-wr6rf3d3vvggy8180ftt2ro1@git.kernel.org
[ Lowercased the directory and file names ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>