Theoretically setting the state to SNDRV_PCM_STATE_DISCONNECTED is
correct.  But, unfortunately, PA gets confused by this action, and it
won't re-probe the device after HDMI/DP is re-plugged.  (It reprobes
only when the card itself is recreated.)

As a workaround, set SNDRV_PCM_STATE_SETUP instead.
Signed-off-by: Takashi Iwai <tiwai@suse.de>