Remove ECDH_RSA, ECDH_ECDSA, DH_RSA, and DH_DSS.

These are the variants where the CA signs a Diffie-Hellman keypair. They are
not supported by Chrome on NSS.

Change-Id: I569a7ac58454bd3ed1cd5292d1f98499012cdf01
Reviewed-on: https://boringssl-review.googlesource.com/1564
Reviewed-by: Adam Langley <agl@google.com>
8 files changed