perf evsel: tp_format accessing improvements

perf evsel: tp_format accessing improvements

Ensure evsel__clone copies the tp_sys and tp_name variables.
In evsel__tp_format, if tp_sys isn't set, use the config value to find
the tp_format. This succeeds in python code where pyrf__tracepoint has
already found the format.

Reviewed-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250228222308.626803-4-irogers@google.com
Fixes: 6c8310e8380d472c ("perf evsel: Allow evsel__newtp without libtraceevent")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>