can: rcar_canfd: Add support for RZ/G2L family

CANFD block on RZ/G2L SoC is almost identical to one found on
R-Car Gen3 SoC's. On RZ/G2L SoC interrupt sources for each channel
are split into different sources and the IP doesn't divide (1/2)
CANFD clock within the IP.

This patch adds compatible string for RZ/G2L family and splits
the irq handlers to accommodate both RZ/G2L and R-Car Gen3 SoC's.

Link: https://lore.kernel.org/r/20210727133022.634-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
[mkl: fixed typo: recieve -> receive, thanks Geert]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>