tcl: move SPDX tag as first line

The SPDX tag is aimed at machine handling and it's thus expected
to be placed in the first line.

Change-Id: I3992856eeb28b333c38d010ef286e22471ede263
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7026
Tested-by: jenkins

tcl/interface/ftdi/snps_sdp.cfg

@@ -1,8 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 #  Copyright (C) 2020 Synopsys, Inc.
 #  Anton Kolesov <anton.kolesov@synopsys.com>
 #  Didin Evgeniy <didin@synopsys.com>
-#
-#  SPDX-License-Identifier: GPL-2.0-or-later
 
 #
 # Synopsys SDP Mainboard has embdded FT2232 chip, which is similar to Digilent