Mazda: find bit to describe temporary steer faults

[sshane]

Right now we just have hardocded values for the steering speeds and some hysteresis logic to check whether we should be able to steer, and if the car is allowing us to steer (based on STEER_RATE->LKAS_BLOCK). However this signal also describes any temporary faults, so we can't fully rely on it for the minimum steer speed alert.

If we find signals to differentiate the reasons of lkas being blocked, we can remove the hard coded speeds and just set the minimum in interface.