Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>