fscrypt: Drop obsolete recommendation to enable optimized NHPoly1305

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>

Author: Eric Biggers

Documentation/filesystems/fscrypt.rst

@@ -455,11 +455,6 @@ API, but the filenames mode still does.
 - Adiantum
     - Mandatory:
         - CONFIG_CRYPTO_ADIANTUM
-    - Recommended:
-        - arm32: CONFIG_CRYPTO_NHPOLY1305_NEON
-        - arm64: CONFIG_CRYPTO_NHPOLY1305_NEON
-        - x86: CONFIG_CRYPTO_NHPOLY1305_SSE2
-        - x86: CONFIG_CRYPTO_NHPOLY1305_AVX2
 
 - AES-128-CBC-ESSIV and AES-128-CBC-CTS:
     - Mandatory: