sh: sh4: convert to SPDX identifiers

Update license to use SPDX-License-Identifier instead of verbose license
text, excepting ${LINUX}/arch/sh/kernel/cpu/sh4/softfloat.c which is not
GPL license

Link: http://lkml.kernel.org/r/87a7lkcsya.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/sh/kernel/cpu/sh4/fpu.c

@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Save/restore floating point context for signal handlers.
  *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
  * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
  * Copyright (C) 2006  ST Microelectronics Ltd. (denorm support)
  *