ASoC: SOF: core/Intel: Introduce DSPless mode

Merge series from Peter Ujfalusi <peter.ujfalusi@linux.intel.com>:

This series will add support for SOF Linux stack to run without using the DSP.

DSPless mode provides a good tool for verification that the hardware itself
works correctly by taking the DSP use out from the picture.
It can only work with interfaces which supports this mode: Intel HDA at the
moment but with LNL it could be possible to support other audio interfaces.

The main driver for this mode is to be able to test programming sequences,
low-level code and for low-level verification of a platform.

The feature is not targetted for end-users and it will not make the SOF stack
to work on hardware without DSP, but it is giving us a tool to debug and enable
platforms earlier (when for example t he firmware is not mature enough).