RZ/G2L has separate IRQ lines for tx and error interrupt for each
channel whereas R-Car has a combined IRQ line for all the channel
specific tx and error interrupts.

Add multi_channel_irqs to struct rcar_canfd_hw_info to select the
driver to choose between combined and separate irq registration for
channel interrupts. This patch also removes enum rcanfd_chip_id and
chip_id from both struct rcar_canfd_hw_info, as it is unused.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/all/20221027082158.95895-6-biju.das.jz@bp.renesas.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>