policy chromium: chromium_tmp_filetrans: doc: add missing 2nd param documentation

Signed-off-by: Markus Linnala <Markus.Linnala@cybercom.com>

policy/modules/apps/chromium.if

@@ -82,6 +82,11 @@ interface(`chromium_rw_tmp_pipes',`
 ##	Domain that creates the resource(s)
 ##	</summary>
 ## </param>
+## <param name="private_type">
+##	<summary>
+##	Private file type.
+##	</summary>
+## </param>
 ## <param name="class">
 ##	<summary>
 ##	Type of the resource created