perf evswitch: Move switch logic to use in other tools

Now other tools that want switching can use an evswitch for that, just
set it up and add it to the PERF_RECORD_SAMPLE processing function.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: William Cohen <wcohen@redhat.com>
Link: https://lkml.kernel.org/n/tip-b1trj1q97qwfv251l66q3noj@git.kernel.org


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