sa2ul.c uses sha{1,256,512}_zero_message_hash, so select the
Kconfig symbols that provide those, like other crypto drivers do.

Fixes this build error:

ld: drivers/crypto/sa2ul.o: in function `sa_sha_digest':
sa2ul.c:(.text+0x2b25): undefined reference to `sha512_zero_message_hash'

Fixes: 7694b6ca ("crypto: sa2ul - Add crypto driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org> # 2020-07-29
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>