BACKPORT, FROMGIT: crypto: nhpoly1305 - add NHPoly1305 support

Add a generic implementation of NHPoly1305, an ε-almost-∆-universal hash
function used in the Adiantum encryption mode.

CONFIG_NHPOLY1305 is not selectable by itself since there won't be any
real reason to enable it without also enabling Adiantum support.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

(cherry picked from commit 26609a21a9460145e37d90947ad957b358a05288
 https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git

 master)

Conflicts:
	crypto/testmgr.c
	crypto/testmgr.h

Bug: 112008522
Test: As series, see Ic61c13b53facfd2173065be715a7ee5f3af8760b
Change-Id: If6f00c01fab530fc2458c44ca111f84604cb85c1
Signed-off-by: Eric Biggers <ebiggers@google.com>