can: rcar_can: Convert to BIT()

Use the BIT() macro instead of open-coding the same operation.
Add a few more comments while at it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/78fb16beb74975f6f6140ec9abb48beb94fb0afa.1755857536.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Geert Uytterhoeven 2025-08-22 12:17:05 +02:00 • committed by Marc Kleine-Budde
commit bcf4dee47f