Disable interrupts to fix a potential race condition.
BLIND_WAIT mode for when the Analog Comparator is busy.

This will be needed if we want to do an ADC read because the Analog
Comparator uses the same multiplexer as the ADC, so either the AC or the
ADC can be used at a time.  It lets the commutation loop skip using the
AC for detecting the zero-crossing and wait blindly for the amount of
time measured in the previous commutation hoping the timing has not
changed drastically.
Define VBAT and Temperature ADC channels in configs.

Only touch bs_nfet.inc and kda.inc for now because these two have been
tested.  We set HAS_TEMPERATURE=0 (i.e temperature not supported) on
both.  The BS might actually also have a sensor connected to one of the
channels but I've bothered to check yet.  The kda (Multistar) definitely
does not :-(
Simple ADC support, read VBAT and temperature.
Trigger an ADC read start once a second.
Make sure to wait_for_power_on even if BEACON=0.
Let the host read VBAT, add dummy 0x1234 to comm counter values.

This lets the Flight Controller read the last voltage value measured by
the ADC using the serial bitbanging protocol.  The dummy 0x1234 value
that is used by the Flight Controller to check if ESC is alive is now
added to the commutation counter so that if the motor is stopped, it can
read it and check if the ESC is alive and protocol version is what it
expects it to be.  If the motor is running and the FC wants the
commutations count instead, it'll need to subtract 0x1234 from the value
received.
Add comment about Vbat divider on MultiStars.
Don't forget to reset READ_ADC when done.