This flattens a license tree by selecting one side of each OR operation
(chosen via the user supplied function).
(From OE-Core rev: 6984961314c8ba2aceab9acabb658f96ed249fef)
Signed-off-by: Christopher Larson <kergoth@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>