package/ipmiutil: fix build with openssl 1.1.x

Fixes:
 - http://autobuild.buildroot.org/results/1d868798c5b80d7b41123f988449ef548dd95490



This works for libressl as well, because libressl does provide
EVP_CIPHER_CTX_new() which is what gets enabled by -DSSL11

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>