CONFIG_CRYPTO_SHA512_ARM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SHA-384/512 digest algorithm (ARM-asm and NEON)

modulename: sha512-arm.ko

configname: CONFIG_CRYPTO_SHA512_ARM

Linux Kernel Configuration
└─>ARM Accelerated Cryptographic Algorithms
└─>SHA-384/512 digest algorithm (ARM-asm and NEON)
In linux kernel since version 3.10 (release Date: 2013-06-30)  
SHA-512 secure hash standard (DFIPS 180-2) implemented
using optimized ARM assembler and NEON, when available.

source code:
/arch/arm/crypto/