default or selected kernelversion does not have config value CONFIG_CRYPTO_SHA256_MB.
Result is shown for kernelversion 6.8.2

SHA256 digest algorithm (x86_64 Multi-Buffer, Experimental)

modulename: sha256-mb.ko

configname: CONFIG_CRYPTO_SHA256_MB

Linux Kernel Configuration
└─>Cryptographic API
└─>SHA256 digest algorithm (x86_64 Multi-Buffer, Experimental)
In linux kernel since version 4.1 (release Date: 2015-06-21)  
SHA-256 secure hash standard (FIPS 180-1/DFIPS 180-2) implemented
using multi-buffer technique. This algorithm computes on
multiple data lanes concurrently with SIMD instructions for
better throughput. It should not be enabled by default but
used when there is significant amount of work to keep the keep
the data lanes filled to get performance benefit. If the data
lanes remain unfilled, a flush operation will be initiated to
process the crypto jobs, adding a slight latency.

source code: