media: intel/ipu6: set the dev_parent of video device to pdev

The bus_info in v4l2_capability of IPU6 isys v4l2_dev is missing.
The driver didn't set the dev_parent of v4l2_dev, its parent is set
to its parent auxdev which is neither platform nor PCI device, thus
media_set_bus_info() will not set the bus_info of v4l2_capability, then
`v4l2-ctl --all` cannot show the bus_info.

This patch fixes it by setting the dev_parent of video_device and v4l2
framework can detect the device type and set the bus_info instead.

Fixes: 3c1dfb5a ("media: intel/ipu6: input system video nodes and buffer queues")
Cc: stable@vger.kernel.org
Signed-off-by: Hidenori Kobayashi <hidenorik@chromium.org>
Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>