Update the license as found in the actual source file, and remove the README
from _LICENSE_FILES as it does not contain anything regarding licenses.
Note that adding the source file as LICENSE_FILE means that the
corresponding hash will be different on every version bump.
Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>