Previously the cpu_list is a string and typically no cpu_list is
passed to __add_event().

Wanting to make events have their cpus distinct from the PMU means that
in more occassions we want to pass a cpu_list.

If we're reading this from sysfs it is easier to read a perf_cpu_map
than allocate and pass around strings that will later be parsed.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Gautham Shenoy <gautham.shenoy@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
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: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20240718003025.1486232-3-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>