sock/dtls: remove sock_dtls_session_create
sock/dtls: remove sock_dtls_session_create

due to deprecation

OTAkeys/RIOT,miri64/RIOT,kaspar030/RIOT,jasonatran/RIOT,ant9000/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,authmillenon/RIOT,authmillenon/RIOT,authmillenon/RIOT,kYc0o/RIOT,OlegHahm/RIOT,kaspar030/RIOT,jasonatran/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,kaspar030/RIOT,kaspar030/RIOT,jasonatran/RIOT,miri64/RIOT,OlegHahm/RIOT,miri64/RIOT,kYc0o/RIOT,ant9000/RIOT,ant9000/RIOT,kaspar030/RIOT,kYc0o/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,authmillenon/RIOT,authmillenon/RIOT,miri64/RIOT,RIOT-OS/RIOT,ant9000/RIOT,ant9000/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,miri64/RIOT,jasonatran/RIOT