CONFIG_CRYPTO_CHACHA_RISCV64 is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT or riscv

Ciphers: ChaCha

modulename: chacha-riscv64.ko

configname: CONFIG_CRYPTO_CHACHA_RISCV64

Linux Kernel Configuration
└─>Accelerated Cryptographic Algorithms for CPU (riscv)
└─>Ciphers: ChaCha
In linux kernel since version 4.19.314 (release Date: 2024-05-17)  
Length-preserving ciphers: ChaCha20 stream cipher algorithm

Architecture: riscv64 using:
- Zvkb vector crypto extension

source code:
/arch/riscv/crypto/