Currently each architecture exposes ChaCha not only through the library API, but also through the crypto_skcipher API. That requires each architecture to implement essentially the same skcipher glue code. Following the example of what's been done for crc32 and crc32c, eliminate this redundancy by making crypto/chacha.c register both the generic and architecture-optimized skcipher algorithms, implemented on top of the appropriate library functions. This removes almost 800 lines of code and disentangles the library code from the skcipher API.
