sparc64: Add symbolic access to M7 performance counters to perf

sparc64: Add symbolic access to M7 performance counters to perf

This commit provides symbolic access to every performance counter
provided in the M7. The 'perf list' command can be used to provide
a complete list of these new events, which will be reported as
shown below.

Br_mispred OR cpu/Br_mispred/                      [Kernel PMU event]
Br_taken OR cpu/Br_taken/                          [Kernel PMU event]
Br_tgt_mispred OR cpu/Br_tgt_mispred/              [Kernel PMU event]

Orabug: 23313970

Note: This commit is based on a cherry-pick of the following:
3bc29d39f2cb5ba72d945d79f82dd0c98dc55643
bd91767dfdbee52537ec3f1454c8c2cf0cf77a84

Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Acked-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>
(cherry picked from commit 39f70b2fa98ea10931133ab983f521c70cb7429f)