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/power/regulator/Makefile b/drivers/power/regulator/Makefile
index 16208af..a5f5683 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -1,9 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
 #
 # Copyright (C) 2015 Samsung Electronics
 # Przemyslaw Marczak <p.marczak@samsung.com>
 #
-# SPDX-License-Identifier:     GPL-2.0+
-#
 
 obj-$(CONFIG_$(SPL_)DM_REGULATOR) += regulator-uclass.o
 obj-$(CONFIG_REGULATOR_ACT8846) += act8846.o