Support the other two NIST curves and their Brainpool counterparts.
* src/ecdh.c (_ntbtls_ecdh_read_params): Add new curves. * src/protocol-cli.c (write_supported_elliptic_curves_ext): Ditto.
- GnuPG-bug-id: T3411
- Signed-off-by: Werner Koch <wk@gnupg.org>