raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

The hardware default is differential CVBS on AIN1 & 2, which
isn't very useful.

Select the first input that is defined as valid for the
chip variant (typically CVBS_AIN1).
Signed-off-by: NDave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>