Add a legal notice about licenses

Build script will copy this file to the toolchain installation directory. As
a result this file will be always present in our official distributables.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Merge branch 'arc-4.8-dev' into arc-releases
Create arc-versions.sh for tag arc-2014.12-rc2