IMU_P6 (SPI1) Workaround is now robust.  Both it and IMU_ONBOARD (SPI6) are passing the 100Hz tests.  The SPI1 bug was pretty serious, it's necessary to reconfigure the device in order to transfer using only a single DMA channel.  Creating a DMA stream manager is now an item in asana.

As an additional concern, this needs to be weighed with some experimentation on reducing the number of SPI ports.  It's possible that 4 ports or fewer could be (considerably) more efficient than re-configuring things between transfers, and managing all of this state-related overhead.

Signed-off-by: Anthony Clay <anthony.clay@zarthcode.com>