can: tcan4x5x: remove duplicate include of regmap.h

linux/regmap.h has been included at line 13, so remove the duplicate
one at line 14.

Fixes: 67def4ef ("can: tcan4x5x: move regmap code into seperate file")
Link: https://lore.kernel.org/r/20210323021026.140460-1-wanjiabing@vivo.com


Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>