CONFIG_CRYPTO_SHA256_OCTEON is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_CRYPTO_SHA256_OCTEON (not configurable)

modulename: octeon-sha256.ko

configname: CONFIG_CRYPTO_SHA256_OCTEON

Linux Kernel Configuration
└─>CRYPTO_SHA256_OCTEON
In linux kernel since version 3.10 (release Date: 2013-06-30)  
source code:
/arch/mips/cavium-octeon/crypto/octeon-sha256.c