media: rcar-vin: Add r8a779a0 support

Add support for the R-Car V3U (r8a779a0) to the driver. The V3U has the
VIN modules connected to a ISP instead of directly to the R-Car CSI-2
receivers. The reason being that the ISP performs channel selection
based on CSI-2 VC/DT pairs and routes the video data to different VIN
modules. In other SoC versions this filtering is done by the VIN modules
themself.

While the media graph is very different from other SoCs the only
difference in operating the VIN modules is that the VC/DT filtering
should be skipped as that is performed by the ISP.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>