media: rzg2l-cru: Add function pointer to configure CSI

Add a `csi_setup` function pointer to the `rzg2l_cru_info` structure and
pass it as part of the OF data. On RZ/G3E and RZ/V2H(P) SoCs, additional
register configurations are required compared to the RZ/G2L SoC.

Modify `rzg2l_cru_csi2_setup()` to be referenced through this function
pointer and update the code to use it accordingly.

This change is in preparation for adding support for RZ/G3E and RZ/V2H(P)
SoCs.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Link: https://lore.kernel.org/r/20250411170624.472257-17-tommaso.merciai.xr@bp.renesas.com


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