buffet: Move platform dependent part of PeerdClient out of libweave Peerd is brillo specific service. BUG=brillo:1267 TEST='FEATURES=test emerge-gizmo buffet' Change-Id: I666da7ba0ed6a6c55472fed8c5f5beb16b562619 Reviewed-on: https://chromium-review.googlesource.com/289914 Reviewed-by: Alex Vakulenko <avakulenko@chromium.org> Reviewed-by: Vitaly Buka <vitalybuka@chromium.org> Commit-Queue: Vitaly Buka <vitalybuka@chromium.org> Tested-by: Vitaly Buka <vitalybuka@chromium.org>