mt76: mt76x02: fix handling MCU timeouts during hw restart

If a MCU timeout occurs before a hw restart completes, another hw restart
is scheduled, and the station state gets corrupted.
To speed up dealing with that, do not issue any MCU commands after the first
timeout, and defer handling timeouts until the reset has completed.
Also ignore errors in MCU commands during start/config to avoid making user
space fail on this condition. If it happens, another restart is scheduled
quickly, and that usually recovers the hardware properly.

Signed-off-by: Felix Fietkau <nbd@nbd.name>