changelog: add changelog for PSA CMAC fix

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/ChangeLog.d/fix-psa-cmac.txt b/ChangeLog.d/fix-psa-cmac.txt
new file mode 100644
index 0000000..e3c8aec
--- /dev/null
+++ b/ChangeLog.d/fix-psa-cmac.txt
@@ -0,0 +1,4 @@
+Bugfix
+   * Fix the build when MBEDTLS_PSA_CRYPTO_CONFIG is enabled and the built-in
+     CMAC is enabled, but no built-in unauthenticated cipher is enabled.
+     Fixes #9209.