ALSA: hda - Add DP-MST support for non-acomp codecs

ALSA: hda - Add DP-MST support for non-acomp codecs

This patch make it possible for non-acomp codecs to set
dyn_pcm_assign/dp_mst and get DP-MST audio support.

Document change notification HDA040-A for the Intel High Definition
Audio 1.0a specification introduces a Device Select verb for Digital
Display Pin Widgets that are multi-stream capable. This verb selects
a Device Entry that is used by subsequent Pin Widget verbs.
Once the Device Entry is selected, all subsequent Pin Widget verbs
controlling the sink device will be directed to the selected Device
Entry until the Device Select verb is updated with a new value.

These Pin Widget verbs include:

  * Connection Select
  * Get Connection List Entry
  * Amplifier Gain/Mute
  * Power State
  * Pin Widget Control
  * ELD Data
  * DIP-Size
  * DIP-Index
  * DIP-Data
  * DIP-XmitCtrl
  * Content Protection Control
  * ASP Channel Mapping

This patch adds calls to snd_hda_set_dev_select() to direct each of
these Pin Widget control verbs to the correct Device Entry.

snd_hda_get_connections() does not return per-device connection
list, therefore make use snd_hda_get_raw_connections() instead of
snd_hda_get_connections().

Signed-off-by: Nikhil Mahale <nmahale@nvidia.com>
Reviewed-by: Aaron Plattner <aplattner@nvidia.com>
Link: https://lore.kernel.org/r/20191119084710.29267-4-nmahale@nvidia.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>