media: b2c2: flexcop: Convert to SPDX identifier

use SPDX-License-Identifier instead of a verbose license text

Link: https://lore.kernel.org/linux-media/20210916020006.8497-1-caihuoqing@baidu.com



CC: Mauro Carvalho Chehab <mchehab@kernel.org>, <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>