barometer readout
add servo submodule
onboardsensors: increase stacksize to avoid stack-overflow
use hardware float for sqrtf
update Makefile, don't use link time optimization

LTO makes debugging difficult
init all uarts, add stdio
Merge branch 'sensor-readout'
sdcard setup
sdio & fatfs working
Merge branch 'sdcard'
ChibiOS: change submodule url
update ChibiOS