crypto: arm/sha256 - move SHA-224/256 ASM/NEON implementation to base layer

This removes all the boilerplate from the existing implementation,
and replaces it with calls into the base layer.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --cc arch/arm/crypto/sha256_glue.c
Simple merge

diff --cc arch/arm/crypto/sha256_glue.h
Simple merge

diff --cc arch/arm/crypto/sha256_neon_glue.c
Simple merge