The radio would stop communicating completely. This issue was easiest to
trigger on AR913x devices, e.g. the TP-Link TL-WR1043ND, but other
hardware was occasionally affected as well.
The most critical issue was a race condition in disabling/enabling IRQs
between the IRQ handler and the IRQ processing tasklet
Signed-off-by: Felix Fietkau <nbd@nbd.name>