ALSA: hda/hdmi: let new platforms assign the pcm slot dynamically

ALSA: hda/hdmi: let new platforms assign the pcm slot dynamically

If the platform set the dyn_pcm_assign to true, it will call
hdmi_find_pcm_slot() to find a pcm slot when hdmi/dp monitor is
connected and need to create a pcm.

So far only intel_hsw_common_init() and patch_nvhdmi() set the
dyn_pcm_assign to true, here we let tgl platforms assign the pcm slot
dynamically first, if the driver runs for a period of time and there
is no regression reported, we could set no_fixed_assgin to true in
the intel_hsw_common_init(), and then set it to true in the
patch_nvhdmi().

This change comes from the discussion between Takashi and
Kai Vehmanen. Please refer to:
https://github.com/alsa-project/alsa-lib/pull/118

Suggested-and-reviewed-by: Takashi Iwai <tiwai@suse.de>
Suggested-and-reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20210301111202.2684-1-hui.wang@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>