use SPDX-License-Identifier instead of a verbose license text
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20210906112302.937-1-caihuoqing@baidu.comSigned-off-by: Daniel Thompson <daniel.thompson@linaro.org>