ALSA: hda/hdmi: Fix the converter allocation for the silent stream

Track the converters handling the silent stream using a new
variable to avoid mixing of the open/close and silent stream
use. This change ensures the proper allocation of the converters.

Fixes: 5f80d6bd ("ALSA: hda/hdmi: Fix the converter reuse for the silent stream")

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20220919135444.3554982-1-perex@perex.cz


Signed-off-by: Takashi Iwai <tiwai@suse.de>