this allows for apps to ask for slightly higher filters with the
software filter and not have it completely ruined by the on-chip DLPF

Add direct-access methods to the base Device class, so that there's a common way of talking to drivers regardless of which of the specialised classes they derive from.

Make the Device destructor public and virtual, so that arbitrary devices can be deleted. Likewise for classes that derive from it.

Make Device::init public so that arbitrary devices can be initialised after being returned by factories.

used in gyro and accel drivers for better filtering

Try to save our sanity a bit and use the generic ringbuffer class rather than re-implementing the wheel.

Move NuttX configurations out of the NuttX tree proper. This reduces the diffs we have to carry against the NuttX upstream repo to just our local patches to the NuttX code itself.