time: Allow later version licensing.

The FSF's Licensing and Compliance Lab noted a discrepancy in the
licensing of several files in the glibc package.

When timespect_get.c was impelemented the license did not include
the standard ", or (at your option) any later version." text.

Change the license in timespec_get.c and all copied files to match
the expected license.

This change was previously approved in principle by the FSF in
RT ticket #1316403. And a similar instance was fixed in
commit 46703efa02.

(cherry picked from commit 91695ee459)

sysdeps/unix/sysv/linux/timespec_get.c

@@ -5,7 +5,7 @@
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
-   version 2.1 of the License.
+   version 2.1 of the License, or (at your option) any later version.
 
    The GNU C Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of

sysdeps/unix/sysv/linux/timespec_getres.c

@@ -5,7 +5,7 @@
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
-   version 2.1 of the License.
+   version 2.1 of the License, or (at your option) any later version.
 
    The GNU C Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of

time/timespec_get.c

@@ -4,7 +4,7 @@
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
-   version 2.1 of the License.
+   version 2.1 of the License, or (at your option) any later version.
 
    The GNU C Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of

time/timespec_getres.c

@@ -5,7 +5,7 @@
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
-   version 2.1 of the License.
+   version 2.1 of the License, or (at your option) any later version.
 
    The GNU C Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of