rc.sensors : start external compass on v4Pro and v5 with temperature compensation and self-calibration at startup

 This backports upstrem NuttX
    ea7b673 - Allow dma in 1 bit mode in STM32F4xxx
    17cbec1 - fix warning from ea7b673
    4795d58 - Only the decoded.oid    = (cid[0] >> 8) change.

  This backports upstrem NuttX
  ea7b673 - Allow dma in 1 bit mode in STM32F4xxx
  4795d58 - Only the decoded.oid    = (cid[0] >> 8) change.

Refresh team list.

   Thanks to Jussi Kivilinna

   https://bitbucket.org/nuttx/nuttx/commits/9169ff6a15fe65ba4af134b470dbf89220274c19

   stm32_serial: fix freezing serial port.  Serial interrupt enable/disable functions
   do not disable interrupts and can freeze device when serial interrupt is received
   while execution is at those functions.

   Trivially triggered with two or more threads write to regular syslog stream and to
   emergency stream. In this case, freeze happens because of mismatch of priv->ie
   (TXEIE == 0) and actually enabled interrupts in USART registers (TXEIE == 1),
   which leads to unhandled TXE interrupt and causes interrupt storm for USART.

Adds parameters so that the motion checks used to switch between magnetic yaw and 3-axis fusion can be adjusted.
Modifies the check used to determine if learned mag biases  can be saved. A cumulated calibration time is used rather than continuous calibration time to allow for for switching in and out of 3-axis fusion mode that is required to do calibration.

Filters the vertical position and 3-axis velocity innovations and sets the local and global position as invalid if they exceed limits during ARMING_STATE_STANDBY.

Used to check if the ekf2 module is failing to keep up with the IMU data

Reduce unnecessary length of state and covariance arrays
Add time slip monitor

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Added maintainers / corrected formatting.

With great power comes great responsibility!

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

It increases the throughput on UDP (from around 2Mb to 2.5Mb), while the
rate via USB & telemetry stay the same.

This is an adjustment due to the changed calling frequency of send()
(was 300 Hz, is now 100 Hz)

This makes also a slight stack size increase necessary (was 284 bytes left)

Will be moved to the receiver thread

Also remove the start() declration (there's no definition of that)