dt-bindings: can: renesas,rcar-canfd: Document R-Car V4M support

dt-bindings: can: renesas,rcar-canfd: Document R-Car V4M support

Document support for the CAN-FD Interface on the Renesas R-Car V4M
(R8A779H0) SoC, which supports up to four channels.

The CAN-FD module on R-Car V4M is very similar to the one on R-Car V4H,
but differs in some hardware parameters, as reflected by the Parameter
Status Information part of the Global IP Version Register.  However,
none of this parameterization should have any impact on the driver, as
the driver does not access any register that is impacted by the
parameterization (except for the number of channels).

Signed-off-by: Duy Nguyen <duy.nguyen.rh@renesas.com>
[geert: Clarify R-Car V4M differences]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/68b5f910bef89508e3455c768844ebe859d6ff1d.1722520779.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>