drivers: cosmetic: Convert SPDX license tags to Linux Kernel style

Complete in the drivers directory the work started with
commit 83d290c56fab ("SPDX: Convert all of our single
license tags to Linux Kernel style").

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/net/pfe_eth/Makefile b/drivers/net/pfe_eth/Makefile
index 6b5248f..ab5a7b2 100644
--- a/drivers/net/pfe_eth/Makefile
+++ b/drivers/net/pfe_eth/Makefile
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
 # Copyright 2015-2016 Freescale Semiconductor, Inc.
 # Copyright 2017 NXP
 #
-# SPDX-License-Identifier:GPL-2.0+
 
 # Layerscape PFE driver
 obj-y += pfe_cmd.o	\