Copyright for libubootenv source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: libubootenv
Source: https://github.com/sbabic/libubootenv

Files: *
Copyright: Stefano Babic 
License: LGPL-2.1+

Files: debian/*
Copyright: 2019 Nobuhiro Iwamatsu 
License: LGPL-2.1+

License: LGPL-2.1+
 This program 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, or (at your option)
 any later version.
 .
 This program 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 Lesser General Public License for more details.
 .
 You should have received a copy of the GNU Lesser General Public
 License along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 .
 On Debian systems, the complete text of the GNU Lesser General Public License
 version 2.1 can be found in /usr/share/common-licenses/LGPL-2.1.