can: dev: add can_state_get_by_berr_counter() to return the CAN state based on the...

can: dev: add can_state_get_by_berr_counter() to return the CAN state based on the current error counters

Some CAN controllers do not have a register that contains the current
CAN state, but only a register that contains the error counters.

Introduce a new function can_state_get_by_berr_counter() that returns
the current TX and RX state depending on the provided CAN bit error
counters.

Link: https://lore.kernel.org/all/20231005-at91_can-rx_offload-v2-1-9987d53600e0@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>