cipher_hmac_sha256{_hw.c, .c, .h}: add initial file for sha256 cipher #1273

Job	Run time
run-checker (enable-asan enable-ubsan no-shared no-asm -DOPENSSL_SMALL_FOOTPRINT)	1m 4s
run-checker (no-ct)	50s
run-checker (no-dso)	51s
run-checker (no-dynamic-engine)	51s
run-checker (no-ec2m)	55s
run-checker (no-engine no-shared)	53s
run-checker (no-err)	51s
run-checker (no-filenames)	53s
run-checker (enable-ubsan no-asm -DOPENSSL_SMALL_FOOTPRINT -fno-sanitize=alignment)	53s
run-checker (no-module)	49s
run-checker (no-ocsp)	50s
run-checker (no-pinshared)	50s
run-checker (no-srp)	51s
run-checker (no-srtp)	51s
run-checker (no-ts)	1m 18s
run-checker (enable-weak-ssl-ciphers)	52s
run-checker (enable-zlib)	51s
	15m 13s

Provide feedback