perf: Document the ABI of perf sysfs entries

perf: Document the ABI of perf sysfs entries

This patchset addes two new sets of files to sysfs for POWER architecture.

	- perf event config format in /sys/devices/cpu/format/event
	- generic and POWER-specific perf events in /sys/devices/cpu/events/

The format of the first file is already documented in:

	sysfs-bus-event_source-devices-format

Document the format of the second set of files '/sys/devices/cpu/events/*'
which would also become part of the ABI.

Changelog[v4]:
	[Jiri Olsa]: Mention that multiple event= like terms can be specified
	in the 'events' file.
	[Jiri Olsa]: Remove the documentation for the 'config format' file
	as it is already documented in 'Documentation/ABI/testing/'.
	[Jiri Olsa]: Move ABI documentation from 'stable/' to 'testing/'

Changelog[v3]:
	[Greg KH] Include ABI documentation.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062645.GG13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>