perf evlist: Introduce append_tp_filter_pid() and append_tp_filter_pids()

We'll need this to support 'perf trace e tracepoint --filter=expr', as
the command line tracepoint filter is attache to the preceding evsel,
just like in 'perf record' and when we go to set pid filters, which we
do at the minimum to filter 'perf trace' own syscalls, we need to
append, not set the tp filter.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-daynpknni44ywuzi8iua57nn@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>