Fix trailing newline getting dropped

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/codegen_driverwrappers/generate_driver_wrappers.py b/scripts/codegen_driverwrappers/generate_driver_wrappers.py
index de5d356..d713f35 100755
--- a/scripts/codegen_driverwrappers/generate_driver_wrappers.py
+++ b/scripts/codegen_driverwrappers/generate_driver_wrappers.py
@@ -8,7 +8,8 @@
 def render(tpl_path):
     path, filename = os.path.split(tpl_path)
     return jinja2.Environment(
-        loader=jinja2.FileSystemLoader(path or './')
+        loader=jinja2.FileSystemLoader(path or './'),
+        keep_trailing_newline=True,
     ).get_template(filename).render()
 
 n = len(sys.argv)