CONFIG_CRYPTO_SHA1_ARM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SHA1 digest algorithm (ARM-asm)

modulename: sha1-arm.ko

configname: CONFIG_CRYPTO_SHA1_ARM

Linux Kernel Configuration
└─>ARM Accelerated Cryptographic Algorithms
└─>SHA1 digest algorithm (ARM-asm)
In linux kernel since version 3.1 (release Date: 2011-10-24)  
SHA-1 secure hash standard (FIPS 180-1/DFIPS 180-2) implemented
using optimized ARM assembler.

source code:
/arch/arm/crypto/