EVP_Digest*: enable SHA3 pre-hashing for ECDSA

Fixes #8957

Signed-off-by: Patrick Steuer <patrick.steuer@de.ibm.com>

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8970)

(cherry picked from commit e8d0678da4942dd027981175b16b6b3162731205)