* Refactored caed(8) to use virtual inheritance for audio
subsystem drivers.
* Reimplemented the HPI driver in 'cae/driver_hpi.cpp' and
'cae/driver_hpi.h'.
* Fixed a bug in 'cae/cae_alsa.cpp' that caused induced noise
when routing passthrough audio.
* Reversed format detection order so as to prefer S32_LE format
over S16_LE in 'cae/cae_alsa.cpp'.