Rename Changelog entries that don't have .txt extension

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/ChangeLog.d/add_final_delay_accessor b/ChangeLog.d/add_final_delay_accessor.txt
similarity index 100%
rename from ChangeLog.d/add_final_delay_accessor
rename to ChangeLog.d/add_final_delay_accessor.txt
diff --git a/ChangeLog.d/add_handshake_completion_accessor b/ChangeLog.d/add_handshake_completion_accessor.txt
similarity index 100%
rename from ChangeLog.d/add_handshake_completion_accessor
rename to ChangeLog.d/add_handshake_completion_accessor.txt
diff --git a/ChangeLog.d/add_own_cid_accessors b/ChangeLog.d/add_own_cid_accessors.txt
similarity index 100%
rename from ChangeLog.d/add_own_cid_accessors
rename to ChangeLog.d/add_own_cid_accessors.txt
diff --git a/ChangeLog.d/asn1write-0-fix b/ChangeLog.d/asn1write-0-fix.txt
similarity index 100%
rename from ChangeLog.d/asn1write-0-fix
rename to ChangeLog.d/asn1write-0-fix.txt