dt-bindings: can: tcan4x5x: fix mram-cfg RX FIFO config

This tcan4x5x only comes with 2K of MRAM, a RX FIFO with a dept of 32
doesn't fit into the MRAM. Use a depth of 16 instead.

Fixes: 4edd396a ("dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver")
Link: https://lore.kernel.org/all/20220119062951.2939851-1-mkl@pengutronix.de


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