crypto: arm64/sha-ce - implement export/import

When an ahash algorithm fallback to another ahash and that fallback is
shaXXX-CE, doing export/import lead to error like this:
alg: ahash: sha1-sun8i-ce export() overran state buffer on test vector 0, cfg=\"import/export\"

This is due to the descsize of shaxxx-ce being larger than struct shaxxx_state
off by an u32.
For fixing this, let's implement export/import which rip the finalize
variant instead of using generic export/import.

Fixes: 6ba6c74d ("arm64/crypto: SHA-224/SHA-256 using ARMv8 Crypto Extensions")
Fixes: 2c98833a ("arm64/crypto: SHA-1 using ARMv8 Crypto Extensions")

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>