CONFIG_CRYPTO_CURVE25519_NEON is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

NEON accelerated Curve25519 scalar multiplication library

modulename: curve25519-neon.ko

configname: CONFIG_CRYPTO_CURVE25519_NEON

Linux Kernel Configuration
└─>ARM Accelerated Cryptographic Algorithms
└─>NEON accelerated Curve25519 scalar multiplication library
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
source code:
/arch/arm/crypto/


is depended by
CONFIG_WIREGUARD