(struct perf_pmu_events_attr) is defined in include/linux/perf_event.h,
but the only "show" for it is in x86 and contains x86 specific stuff.

Make a generic one for those of us who are just using the event_str.
Signed-off-by: NCody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>