CONFIG_CRYPTO_NHPOLY1305_NEON, CONFIG_CRYPTO_NHPOLY1305_SSE2, and
CONFIG_CRYPTO_NHPOLY1305_AVX2 no longer exist. The equivalent
optimizations are now just enabled automatically when Adiantum support
is enabled. Update the fscrypt documentation accordingly.
Link: https://lore.kernel.org/r/20251211011846.8179-13-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>