arm: dts: am3x: Update devicetree header comments to sync with v6.3-rc6

Signed-off-by: Andrew Davis <afd@ti.com>
diff --git a/arch/arm/dts/am35xx-clocks.dtsi b/arch/arm/dts/am35xx-clocks.dtsi
index 00dd1f0..220d0a5 100644
--- a/arch/arm/dts/am35xx-clocks.dtsi
+++ b/arch/arm/dts/am35xx-clocks.dtsi
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Device Tree Source for OMAP3 clock data
  *
  * Copyright (C) 2013 Texas Instruments, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 &scm_clocks {
 	emac_ick: emac_ick@32c {