changelog: add missing newline

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/ChangeLog.d/7764.txt b/ChangeLog.d/7764.txt
index be332cd..5eb14b4 100644
--- a/ChangeLog.d/7764.txt
+++ b/ChangeLog.d/7764.txt
@@ -1,4 +1,4 @@
 Features
    * mbedtls_ecc_group_to_psa() and mbedtls_ecc_group_from_psa() helper
      functions were added to convert from mbedtls_ecp_group_id to
-     psa_ecc_family_t and curve's bit size and viceversa, respectively.
\ No newline at end of file
+     psa_ecc_family_t and curve's bit size and viceversa, respectively.