media: ti: cal: Add streams support

media: ti: cal: Add streams support

Add multiplexed streams support. CAL has 8 DMA-engines and can capture 8
separate streams at the same time. The driver filters the streams based
on CSI-2 virtual channel number and datatype. CAL may have (depending on
the SoC) two CSI-2 RX blocks, which share the 8 DMA-engines, so the
number of capturable streams does not change even if there are two CSI-2
RX blocks.

Add 8 video device nodes, each representing a single DMA-engine, and set
the number of source pads on CSI-2 RX blocks to 8. Each video node can be
connected to any of the source pads on either of the CSI-2 RX instances
using media links. CSI-2 RX block's subdevice internal routing is used
to route the incoming CSI-2 streams to one of the 8 source pads.

Only video data streams are supported at the moment.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>