README.license: Update to reflect SPDX tag usage

Update README.license since files now have SPDX tags rather than license
text. Adding a copy of BSD-2-Clause license since that no longer exists
within the project.

Signed-off-by: Rob Herring <robh@kernel.org>
Message-Id: <20190620211944.9378-8-robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

BSD-2-Clause

@@ -0,0 +1,32 @@
+Valid-License-Identifier: BSD-2-Clause
+SPDX-URL: https://spdx.org/licenses/BSD-2-Clause.html
+Usage-Guide:
+  To use the BSD 2-clause "Simplified" License put the following SPDX
+  tag/value pair into a comment according to the placement guidelines in
+  the licensing rules documentation:
+    SPDX-License-Identifier: BSD-2-Clause
+License-Text:
+
+Copyright (c) <year> <owner> . All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.

README.license

@@ -8,7 +8,7 @@ dtc does not incorporate or rely on libfdt for its operation, nor vice
 versa.  It is important that these two pieces of software have
 different license conditions.
 
-As the copyright banners in each source file attest, dtc is licensed
+As SPDX license tags in each source file attest, dtc is licensed
 under the GNU GPL.  The full text of the GPL can be found in the file
 entitled 'GPL' which should be included in this package.  dtc code,
 therefore, may not be incorporated into works which do not have a GPL
@@ -16,10 +16,10 @@ compatible license.
 
 libfdt, however, is GPL/BSD dual-licensed.  That is, it may be used
 either under the terms of the GPL, or under the terms of the 2-clause
-BSD license (aka the ISC license).  The full terms of that license are
-given in the copyright banners of each of the libfdt source files.
-This is, in practice, equivalent to being BSD licensed, since the
-terms of the BSD license are strictly more permissive than the GPL.
+BSD license (aka the ISC license).  The full terms of that license can
+be found are in the file entitled 'BSD-2-Clause'. This is, in
+practice, equivalent to being BSD licensed, since the terms of the BSD
+license are strictly more permissive than the GPL.
 
 I made the decision to license libfdt in this way because I want to
 encourage widespread and correct usage of flattened device trees,