ALSA: hda - Don't enable auto-mute but for speakers in patch_realtek.c

Enable auto-muting in model=auto only for devices with HP and speakers.
For devices with HP and line-outs, don't enable the auto-muting.

Also, add a debug print to show the auto-mute feature.

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