Add a ChangeLog entry for changes so far
mbed TLS ChangeLog (Sorted per branch, date)
+= mbed TLS 2.y.0 released YYYY-MM-DD
+
+Features
+ * Add support for restartable ECC operations, controlled by
+ MBEDTLS_ECP_RESTARTABLE (disabled by default), using new xxx_restartable
+ functions in ECP, ECDSA, PK, and using existing functions in ECDH.
+
= mbed TLS x.x.x branch released xxxx-xx-xx
Security
