raspberrypi inclusion
category: feature
bugzilla: 50432

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Add support for an optional GPIO connected to PWDN on the sensor.
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>