can: tcan4x5x: fix max register value

This patch fixes the max register value for the regmap.
Reviewed-by: NDan Murphy <dmurphy@ti.com>
Tested-by: NSean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-12-mkl@pengutronix.deSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/m_can/tcan4x5x-regmap.c

@@ -12,7 +12,7 @@
 #define TCAN4X5X_WRITE_CMD (0x61 << 24)
 #define TCAN4X5X_READ_CMD (0x41 << 24)
 
-#define TCAN4X5X_MAX_REGISTER 0x8fff
+#define TCAN4X5X_MAX_REGISTER 0x8ffc
 
 static int tcan4x5x_regmap_gather_write(void *context, const void *reg,
 					size_t reg_len, const void *val,