dt-bindings: i3c: Add Renesas I3C controller

Add Renesas I3C controller which is available in R9A08G045 (RZ/G3S) and
R9A09G047 (RZ/G3E) SoCs.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250724094146.6443-4-wsa+renesas@sang-engineering.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>