[newlib-cygwin] include: further adoption of SPDX licensing ID tags.

[newlib-cygwin] include: further adoption of SPDX licensing ID tags.

[Sebastian Huber]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=1329e846c795eb75ba61f178ee8ef931040fcfc1

commit 1329e846c795eb75ba61f178ee8ef931040fcfc1
Author: pfg <pfg@FreeBSD.org>
Date:   Mon Nov 20 19:45:28 2017 +0000

    include: further adoption of SPDX licensing ID tags.
    
    Mainly focus on files that use BSD 3-Clause license.
    
    The Software Package Data Exchange (SPDX) group provides a specification
    to make it easier for automated tools to detect and summarize well known
    opensource licenses. We are gradually adopting the specification, noting
    that the tags are considered only advisory and do not, in any way,
    superceed or replace the license texts.
    
    Special thanks to Wind River for providing access to "The Duke of
    Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
    starting point.

Diff:
---
 newlib/libc/sys/rtems/include/arpa/inet.h | 4 +++-
 newlib/libc/sys/rtems/include/netdb.h     | 2 ++
 newlib/libc/sys/rtems/include/termios.h   | 2 ++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/newlib/libc/sys/rtems/include/arpa/inet.h b/newlib/libc/sys/rtems/include/arpa/inet.h
index 91e3a82..14cd24e 100644
--- a/newlib/libc/sys/rtems/include/arpa/inet.h
+++ b/newlib/libc/sys/rtems/include/arpa/inet.h
@@ -1,4 +1,6 @@
-/*
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
  * ++Copyright++ 1983, 1993
  * -
  * Copyright (c) 1983, 1993
diff --git a/newlib/libc/sys/rtems/include/netdb.h b/newlib/libc/sys/rtems/include/netdb.h
index ff7a7ab..0e64a9c 100644
--- a/newlib/libc/sys/rtems/include/netdb.h
+++ b/newlib/libc/sys/rtems/include/netdb.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
  * Copyright (c) 1980, 1983, 1988, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
diff --git a/newlib/libc/sys/rtems/include/termios.h b/newlib/libc/sys/rtems/include/termios.h
index 0e8918e..5ada6cd 100644
--- a/newlib/libc/sys/rtems/include/termios.h
+++ b/newlib/libc/sys/rtems/include/termios.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
  * Copyright (c) 1988, 1989, 1993, 1994
  *	The Regents of the University of California.  All rights reserved.
  *