can: kvaser_pciefd: Sort register definitions

Sort the registers defines, in the same order as the register bits/fields
are defined.
Sort register bits/fields in MSB-to-LSB order.
Update and add comments.

Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20230529134248.752036-11-extja@kvaser.com


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