perf vendor events arm64: Add topdown L1 metrics for neoverse-n2-v2

Add general topdown L1 metrics for neoverse-n2-v2. Due to the wrong
count of stall_slot and stall_slot_frontend on neoverse-n2, the real
stall_slot and real stall_slot_frontend need to subtract cpu_cycles,
so overwrite the "MetricExpr" for neoverse-n2 which slots are 5.
Reference from ARM neoverse-n2 errata notice [0], D117.

Since neoverse-n2/neoverse-v2 does not yet support topdown L2, metric
groups such as Cache, TLB, Branch, InstructionsMix and PEutilization
will be added to further analysis of performance bottlenecks in the
following patches. Reference from ARM PMU guide [1][2].

[0] https://documentation-service.arm.com/static/636a66a64e6cf12278ad89cb?token=
[1] https://documentation-service.arm.com/static/628f8fa3dfaf015c2b76eae8?token=
[2] https://documentation-service.arm.com/static/62cfe21e31ea212bb6627393?token=Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Kilroy <andrew.kilroy@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuai Xue <xueshuai@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: Zhuo Song <zhuo.song@linux.alibaba.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/1673940573-90503-5-git-send-email-renyu.zj@linux.alibaba.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/pmu-events/arch/arm64/arm/neoverse-n2-v2/metrics.json

+[
+    {
+        "ArchStdEvent": "FRONTEND_BOUND",
+        "MetricExpr": "((stall_slot_frontend) if (#slots - 5) else (stall_slot_frontend - cpu_cycles)) / (#slots * cpu_cycles)"
+    },
+    {
+        "ArchStdEvent": "BAD_SPECULATION",
+        "MetricExpr": "(1 - op_retired / op_spec) * (1 - (stall_slot if (#slots - 5) else (stall_slot - cpu_cycles)) / (#slots * cpu_cycles))"
+    },
+    {
+        "ArchStdEvent": "RETIRING",
+        "MetricExpr": "(op_retired / op_spec) * (1 - (stall_slot if (#slots - 5) else (stall_slot - cpu_cycles)) / (#slots * cpu_cycles))"
+    },
+    {
+        "ArchStdEvent": "BACKEND_BOUND"
+    }
+]