SOF client support (auxiliary bus)

[ujfalusi]

Hi,

this series is relatively big departure from previous versions (the latest was #2836 from me).
The high level concept is:

• SOF client are auxiliary devices / drivers (sof_client_drv level is dropped)
• The API used by clients are going to be sof_client_*
  • we will add new ones as the need emerges
• platform dependent and dynamic information can be passed to the client driver via standard device platform_data
• platform dependent static information, parameters which can be local to the client driver can be propagated via match with different device name.
• In case the platform needs host side software control like HDA does, the platform_data is the place to give the ops to the client driver along with a parameter that the callbacks should be called with (void *host_data) and it is up to the host side code to cast it to what it is using internally.
  • see the sof-client-probes and hda-probes pair.

Dropped most of the reviewed-by, tested-by tags since not much is intact from the original versions, but I have kept @ranj063 as author where she was and @fredoh9 as co-author.
I have tested the IPC flood test with 3 instance and the probes on my TGL-H HDA device, all works correctly.

Reasons for a draft status:

• the sound card created by the probes takes card0 with a single compr, the normal audio card is enumerated as card1
  • I want to find a way to keep the audio card as card0 and have the probes at card1
  • I'm not sure if this actually matters.
• I have tried to split up the probes conversion patch (last one), but I just don't see how it can be done in a bisectable way
• I might have missed some of the comments for the previous approach, but I have tried, some of them no longer applicable
• I want to see if I can also move the trace support out as a client as next step.

Next steps:

• split up the snd_sof_dsp_ops into chunks for the really core DSP/Firmware management, communication and audio, trace to prepare for the audio support client conversion.
• abstract away all platform specific members from snd_sof_pdata, sof_dev_desc, snd_sof_dev and other structures under a void * and make them only visible for the platform they are actually used (whenever it is possible)
• IO function abstraction break up
• work towards full client based setup of SOF.