With the goal of supporting pmu-events test case, introduce support for
a test events folder.

These test events can be used for testing generation of pmu-event tables
and alias creation for any arch.

When running the pmu-events test case, these test events will be used as
the platform-agnostic events, so aliases can be created per-PMU and
validated against known expected values.

To support the test events, add a "testcpu" entry in pmu_events_map[].
The pmu-events test will be able to lookup the events map for "testcpu",
to verify the generated tables against expected values.

The resultant generated pmu-events.c will now look like the following:

  struct pmu_event pme_ampere_emag[] = {
  {
  	.name = "ldrex_spec",
  	.event = "event=0x6c",
  	.desc = "Exclusive operation spe...",
  	.topic = "intrinsic",
  	.long_desc = "Exclusive operation ...",
  },
  ...
  };

  struct pmu_event pme_test_cpu[] = {
  {
  	.name = "uncore_hisi_ddrc.flux_wcmd",
  	.event = "event=0x2",
  	.desc = "DDRC write commands. Unit: hisi_sccl,ddrc ",
  	.topic = "uncore",
  	.long_desc = "DDRC write commands",
  	.pmu = "hisi_sccl,ddrc",
  },
  {
  	.name = "unc_cbo_xsnp_response.miss_eviction",
  	.event = "umask=0x81,event=0x22",
  	.desc = "Unit: uncore_cbox A cross-core snoop resulted ...",
  	.topic = "uncore",
  	.long_desc = "A cross-core snoop resulted from L3 ...",
  	.pmu = "uncore_cbox",
  },
  {
  	.name = "eist_trans",
  	.event = "umask=0x0,period=200000,event=0x3a",
  	.desc = "Number of Enhanced Intel SpeedStep(R) ...",
  	.topic = "other",
  },
  {
  	.name = 0,
  },
  };

  struct pmu_events_map pmu_events_map[] = {
  ...
  {
  	.cpuid = "0x00000000500f0000",
  	.version = "v1",
  	.type = "core",
  	.table = pme_ampere_emag
  },
  ...
  {
  	.cpuid = "testcpu",
  	.version = "v1",
  	.type = "core",
  	.table = pme_test_cpu,
  },
  {
  	.cpuid = 0,
  	.version = 0,
  	.type = 0,
  	.table = 0,
  },
  };
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linuxarm@huawei.com
Link: http://lore.kernel.org/lkml/1584442939-8911-3-git-send-email-john.garry@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>