e_devcrypto: make the /dev/crypto engine dynamic

Engine has been moved from crypto/engine/eng_devcrypto.c to
engines/e_devcrypto.c.

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7859)