EVP_EncryptInit.pod: EVP_CIPHER_mode and EVP_CIPHER_CTX_mode update

Mention CTR, GCM, CCM, OCB, WRAP and XTS modes.

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

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4498)