Stop using composite EVP_CIPHER AEADs.

Stop using composite EVP_CIPHER AEADs.

The composite AEADs are "stitched" mode ciphers, that are only supported on
some architectures/CPUs and are designed to be faster than a separate
EVP_CIPHER and EVP_MD implementation. The three AEADs are used for less
than ideal cipher suites (if you have hardware support that these use
there are better cipher suite options), plus continuing to support AEADs
via EVP_CIPHER is creating additional code complexity.

ok inoguchi@ tb@