can: rockchip_canfd: CAN_ROCKCHIP_CANFD should depend on ARCH_ROCKCHIP

The Rockchip CAN-FD controller is only present on Rockchip SoCs. Hence
add a dependency on ARCH_ROCKCHIP, to prevent asking the user about
this driver when configuring a kernel without Rockchip platform
support.

Fixes: ff60bfba ("can: rockchip_canfd: add driver for Rockchip CAN-FD controller")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/a4b3c8c1cca9515e67adac83af5ba1b1fab2fcbc.1727169288.git.geert+renesas@glider.be


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>