media: staging: rkisp1: add streaming paths

Add v4l2 capture device interface to rkisp1 driver, allowing users to
get frames from ISP1.
ISP1 has two major streaming paths, mainpah and selfpah, with different
capabilities.
Each one has an independent crop and resizer, thus add a capture video
device and a resizer subdevice for each of the paths.

Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
Signed-off-by: Shunqian Zheng <zhengsq@rock-chips.com>
Signed-off-by: Yichong Zhong <zyc@rock-chips.com>
Signed-off-by: Jacob Chen <cc@rock-chips.com>
Signed-off-by: Eddie Cai <eddie.cai.linux@gmail.com>
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Allon Huang <allon.huang@rock-chips.com>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>