It is an existing convention to use suffixes with PMU names. Try to
capture that convention so that future PMU devices may adhere to it.
The name of the file and date within the file try to follow existing
conventions, particularly sysfs-bus-event_source-devices-events.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>