Add changeLog entry

Add changeLog entry with the additional oid for "Any Policy".
diff --git a/ChangeLog b/ChangeLog
index 9deefa5..5eebec1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,8 @@
    * Add MBEDTLS_REMOVE_3DES_CIPHERSUITES to allow removing 3DES ciphersuites
      from the default list (enabled by default). See
      https://sweet32.info/SWEET32_CCS16.pdf.
+   * Add the Any Policy certificate policy oid, as defined in
+     rfc 5280 section 4.2.1.4.
 
 API Changes
    * Add a new X.509 API call `mbedtls_x509_parse_der_nocopy()`.