can: tcan4x5x: Remove reserved register 0x814 from writable table

The mentioned register is not writable. It is reserved and should not be
written.

Fixes: 39dbb21b ("can: tcan4x5x: Specify separate read/write ranges")
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Link: https://lore.kernel.org/all/20230728141923.162477-3-msp@baylibre.com


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