perf evsel: Add evsel__open_per_cpu_and_thread

perf evsel: Add evsel__open_per_cpu_and_thread

Add evsel__open_per_cpu_and_thread that combines the operation of
evsel__open_per_cpu and evsel__open_per_thread so that an event
without the "any" cpumask can be opened with its cpumask and with
threads it specifies. Change the implementation of evsel__open_per_cpu
and evsel__open_per_thread to use evsel__open_per_cpu_and_thread to
make the implementation of those functions clearer.

Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250719030517.1990983-12-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>