am 0d5fd3fc: am aab6d576: Revert "ECIES: add HKDF (specified in RFC 5869) using HMAC-SHA256"

* commit '0d5fd3fc54895cd74a24ca53b7c871bc6d47794c':
  Revert "ECIES: add HKDF (specified in RFC 5869) using HMAC-SHA256"