can: mcp251xfd: fix ring configuration when switching from CAN-CC to CAN-FD mode

can: mcp251xfd: fix ring configuration when switching from CAN-CC to CAN-FD mode

If the ring (rx, tx) and/or coalescing parameters (rx-frames-irq,
tx-frames-irq) have been configured while the interface was in CAN-CC
mode, but the interface is brought up in CAN-FD mode, the ring
parameters might be too big.

Use the default CAN-FD values in this case.

Fixes: 9263c2e92be9 ("can: mcp251xfd: ring: add support for runtime configurable RX/TX ring parameters")
Link: https://lore.kernel.org/all/20240805-mcp251xfd-fix-ringconfig-v1-1-72086f0ca5ee@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>