UPSTREAM: crypto: arm64/sha2-ce - implement ->digest for sha256

Implement a ->digest function for sha256-ce.  This improves the
performance of crypto_shash_digest() with this algorithm by reducing the
number of indirect calls that are made.  This only adds ~112 bytes of
code, mostly for the inlined init, as the finup function is tail-called.

For now, don't bother with this for sha224, since sha224 is rarely used.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Bug: 330611177
(cherry picked from commit 1efcbf0e)
Change-Id: I6916d04d29a9ebee64e5b9ce1f5386864afcf7cb
Signed-off-by: Eric Biggers <ebiggers@google.com>