openssl: remove obsolete patch files

These patches were provided by Android and Chromium. In this form they
are not useful. The ones that we need are landed as separate commits.

As of openssl 1.0.1c, three of them made it upstream:
  * npn.patch (Next Protocol Negotiation support)
  * tls_exporter.patch (RFC 5705 Keying Material Exporters for TLS)
  * openssl_no_dtls1.patch (minor bugfix)