ALSA: hda/hdmi - Clear codec->relaxed_resume flag at unbinding

The HDMI codec may leave codec->relaxed_resume flag set even after
unbinding.  Clear it unconditionally.

It's very unlikely that this actually matters in the real use case,
so just a fix for consistency.

Fixes: ade49db3

 ("ALSA: hda/hdmi - Allow audio component for AMD/ATI and Nvidia HDMI")
Link: https://lore.kernel.org/r/20191122132624.5482-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>