Improve changelog

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/ChangeLog.d/add_psa_m_aead.txt b/ChangeLog.d/add_psa_m_aead.txt
index 3ae5809..fa4e7ac 100644
--- a/ChangeLog.d/add_psa_m_aead.txt
+++ b/ChangeLog.d/add_psa_m_aead.txt
@@ -1,4 +1,3 @@
 Features
-   * Added multipart AEAD API to the PSA Crypto API
-   * Added MbedTLS internal implementations of the PSA Crypto multipart AEAD API
-     supporting ChaChaPoly and GCM. CCM is not as yet supported.
+   * Implement the PSA multipart AEAD interface, currently supporting
+     ChaChaPoly and GCM.