perf cs-etm: Improve version detection and error reporting

perf cs-etm: Improve version detection and error reporting

When the config validation functions are warning about ETMv3, they do it
based on "not ETMv4". If the drivers aren't all loaded or the hardware
doesn't support Coresight it will appear as "not ETMv4" and then Perf
will print the error message "... not supported in ETMv3 ..." which is
wrong and confusing.

cs_etm_is_etmv4() is also misnamed because it also returns true for
ETE because ETE has a superset of the ETMv4 metadata files. Although
this was always done in the correct order so it wasn't a bug.

Improve all this by making a single get version function which also
handles not present as a separate case. Change the ETMv3 error message
to only print when ETMv3 is detected, and add a new error message for
the not present case.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Leo Yan <leo.yan@linux.dev>
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
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: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240501135753.508022-4-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>