This patch moves all CAN frame length related code of the CAN device
infrastructure into a separate file.
Reviewed-by: NVincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-5-mkl@pengutronix.deSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>