/dev/crypto engine: add missing RC4 parameter

Fixes #7280

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/7281)

(cherry picked from commit f52f2c1a)