Add GPL-2.0+ SPDX-License-Identifier to source files

Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/post/lib_powerpc/fpu/darwin-ldouble.c b/post/lib_powerpc/fpu/darwin-ldouble.c
index 41ae202..faf9a94 100644
--- a/post/lib_powerpc/fpu/darwin-ldouble.c
+++ b/post/lib_powerpc/fpu/darwin-ldouble.c
@@ -7,29 +7,8 @@
 
 This file is part of GCC.
 
-GCC is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
-version.
-
-In addition to the permissions in the GNU General Public License, the
-Free Software Foundation gives you unlimited permission to link the
-compiled version of this file into combinations with other programs,
-and to distribute those combinations without any restriction coming
-from the use of this file.  (The General Public License restrictions
-do apply in other respects; for example, they cover modification of
-the file, and distribution when not linked into a combine
-executable.)
-
-GCC is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-for more details.
-
-You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING.  If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA.  */
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
 
 /*
  * Implementations of floating-point long double basic arithmetic