Import peerd/ from the chromiumos platform2 repo

Copy the unchanged source tree from the peerd/ directory of
https://chromium.googlesource.com/chromiumos/platform2

At the time, platform2 master was:
14764a942acd7bc4d771745384026e1258e12bae
and the most recent commit to the peerd directory was:
744028ba22ada35a82534586b02880fc2ce4f151

Bug: 22979013