ASoC: SOF: Intel: improve SoundWire support for

ASoC: SOF: Intel: improve SoundWire support for

Merge series from Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>:

This patchset contains important updates for SoundWire support.

We initially implemented support for multiple amplifiers on different
links using a single HDaudio DMA transfer. To align with the other OS,
the 'aggregation' is now supported by the firmware. This change in
directions has kernel impacts, since we now have multiple HDaudio DMAs
to program and start, but since there are no platforms released so far
there's no end-user impact.

In addition, the behavior in case of xruns is improved by clearing the
PCM states and better handling of the hw_free case.

Note that the hw_free support will compile but will only be functional
with the companion patch "soundwire: intel: add intel_free_stream() back"
already applied in the SoundWire tree.