can: rcar_canfd: Remove superfluous parentheses in address calculations

There is no need to wrap simple variables or multiplications inside
parentheses.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/b5aee80895fa029070fd37d1d837cf1c0ecb52dc.1716973640.git.geert+renesas@glider.be


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