media: rcar-csi2: Add D-PHY support for V4H

Add D-PHY support for V4H in addition to the already supported C-PHY.
The common start-up procedure for C-PHY and D-PHY is shared, only PHY
setup differ. Extend the V4H setup with D-PHY support as documented in
the datasheet (Rev.1.21).

Most of the start-up procedure is only documented as magic values in
tables, there is little documentation to make the settings more clear.
Wherever possible formulas or lookup tables are used as they are
documented in the datasheet.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20250612175904.1126717-5-niklas.soderlund+renesas@ragnatech.se


Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>