- increase stack sizes to run cleanly under stackcheck
- this is likely overkill for most boards, but using stackcheck to set our minimum ensures we have a very safe margin on regular builds and it's something we can currently afford
- remove holybro_durandal-v1_stackcheck from test rack (there's only one unit)
- update to NuttX with stm32f4 and stm32f7 SPI DMA internal buffers
- remove explicit DMA buffer allocations from new IMU drivers
- restore original BOARD_DMA_ALLOC_POOL_SIZE
- decrease SPI DMA thresholds based on fmu-v2/v3/v4/v5 bench testing
- uses the FIFO and SPI DMA to transfer full raw data (8 kHz gyro, 4 kHz accel)
- new sensor messages for better visibility
- sensor_{accel, gyro}_fifo: full raw data for optional logging and analysis
- sensor_{accel, gyro}_status: metadata, clipping, etc
- currently not enabled by default
* The build is built with SPI4. At run time the signal GPIO_8266_GPIO2 it tested. If it is low the SPI4 is configured. If it is high SPI4 is not configured.
* board_common: Add Notion of Board has bus manifest