Add Changelog for the Marvin attack fix

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/ChangeLog.d/fix-Marvin-attack.txt b/ChangeLog.d/fix-Marvin-attack.txt
new file mode 100644
index 0000000..f729304
--- /dev/null
+++ b/ChangeLog.d/fix-Marvin-attack.txt
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+Security
+   * Fix a timing side channel in RSA private operations. This side channel
+     could be sufficient for a local attacker to recover the plaintext. It
+     requires the attecker to send a large number of messages for decryption.
+     For details, see "Everlasting ROBOT: the Marvin Attack", Hubert Kario.
+     Reported by Hubert Kario, Red Hat.