can: c_can: C_CAN: add bus recovery events

While the state is updated when the error counters increase and
decrease, there is no event when the bus recovers and the error counters
decrease again. So add that event as well.

Change the state going downward to be ERROR_PASSIVE -> ERROR_WARNING ->
ERROR_ACTIVE instead of directly to ERROR_ACTIVE again.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Tested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>