can: tcan4x5x: regmap: fix max register value

can: tcan4x5x: regmap: fix max register value

[ Upstream commit e59986de5ff701494e14c722b78b6e6d513e0ab5 ]

The MRAM of the tcan4x5x has a size of 2K and starts at 0x8000. There
are no further registers in the tcan4x5x making 0x87fc the biggest
addressable register.

This patch fixes the max register value of the regmap config from
0x8ffc to 0x87fc.

Fixes: 6e1caaf8ed22 ("can: tcan4x5x: fix max register value")
Link: https://lore.kernel.org/all/20220119064011.2943292-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>