ChangeLog.d/rename-conf-early-data-API.txt

API changes
   * Remove `tls13_` in mbedtls_ssl_tls13_conf_early_data() and
     mbedtls_ssl_tls13_conf_max_early_data_size() API names. Early data
     feature may not be TLS 1.3 specific in the future. Fixes #6909.