media: rzg2l-cru: Add register mapping support

Prepare for adding support for RZ/G3E and RZ/V2HP SoCs, which have a
CRU-IP that is mostly identical to RZ/G2L but with different register
offsets and additional registers. Introduce a flexible register mapping
mechanism to handle these variations.

Define the `rzg2l_cru_info` structure to store register mappings and
pass it as part of the OF match data. Update the read/write functions
to check out-of-bound accesses and use indexed register offsets from
`rzg2l_cru_info`, ensuring compatibility across different SoC variants.

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/20250411170624.472257-12-tommaso.merciai.xr@bp.renesas.com


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