Add ChangeLog entry for platform setup and teardown
diff --git a/ChangeLog b/ChangeLog
index 0209cfe..937991a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,16 @@
 
 = mbed TLS x.x.x branch released xxxx-xx-xx
 
+Features
+   * Add the functions mbedtls_platform_setup() and mbedtls_platform_teardown()
+     to perform platform-specific setup and teardown operations. Furthermore,
+     the internal functions mbedtls_internal_platform_setup() and
+     mbedtls_internal_platform_teardown() to allow platform-specific hooks to
+     be plugged into the library. Finally, the macro MBEDTLS_PLATFORM_SETUP_ALT
+     allows the internal functions to be overridden. This new APIs are
+     specially useful in some embedded environments that have hardware
+     acceleration support.
+
 API Changes
    * Reverted API/ABI breaking changes introduced in mbed TLS 2.5.1, to make the
      API consistent with mbed TLS 2.5.0. Specifically removed the inline