[system] add apt preference file for lpc21isp package
additionals to use amsys sensors to measure airspeed
[math] fix ecef_of_[ned|enu]_i
[modules] remove unused baro_x_updated vars
[math] buf fix on geodetic function
[rotorcraft] add MODE_STARTUP to make flying without RC possible

Based on Freek van Tienen's commit, thx.
closes #467 for now
[lpc21] print error if trying to use SPI0 with HAL
[boards][krooz_sd] fix PPM Capture/Compare InterruptEnable define
[stm32] include stm32/flash.h instead of f1/4 variants
[superbitrf] Initial commit for superbitrf 2.4GHz radio control
[superbitrf] Now got a full RC working, still needs testing.

Binding could be improved but already works about 30% of the times you try.
[superbitrf] Less RC Lost and fixed message

Implemented to make it only resyncing when it lost 2 packets of data. Also fixed the message to show the correct status of the CYRF6936.
[superbitrf] Downlink is now functional

Still needs some extensive testing to make it more relaible.