When trying to add events to multiple PMUs the term list is copied first
as adding the event will rewrite the event's name term into the sysfs
and/or json encoding terms (see perf_pmu__check_alias).

Change the parse events add API so the passed in term list is const,
then copy the list when modification is necessary.
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Ian Rogers <irogers@google.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: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230901233949.2930562-5-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>