crypto: mips/poly1305 - incorporate OpenSSL/CRYPTOGAMS optimized implementation

This is a straight import of the OpenSSL/CRYPTOGAMS Poly1305 implementation for
MIPS authored by Andy Polyakov, a prior 64-bit only version of which has been
contributed by him to the OpenSSL project. The file 'poly1305-mips.pl' is taken
straight from this upstream GitHub repository [0] at commit
d22ade312a7af958ec955620b0d241cf42c37feb, and already contains all the changes
required to build it as part of a Linux kernel module.

[0] https://github.com/dot-asm/cryptogams



Co-developed-by: Andy Polyakov <appro@cryptogams.org>
Signed-off-by: Andy Polyakov <appro@cryptogams.org>
Co-developed-by: René van Dorst <opensource@vdorst.com>
Signed-off-by: René van Dorst <opensource@vdorst.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>