ALSA: hda - Add digital beep playback switch for STAC/IDT codecs

The digital beep widget may have no mute control, and always enabling
the beep is ofen pretty annoying, especially on laptops.

This patch adds a mixer control "PC Beep Playback Switch" when there
is no mixer amp mute is found, and controls it on software.

Reference: Novell bnc#444572
	https://bugzilla.novell.com/show_bug.cgi?id=444572

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_beep.h b/sound/pci/hda/hda_beep.h
index de4036e..b9679f0 100644
--- a/sound/pci/hda/hda_beep.h
+++ b/sound/pci/hda/hda_beep.h
@@ -31,6 +31,7 @@
 	char phys[32];
 	int tone;
 	int nid;
+	int enabled;
 	struct work_struct beep_work; /* scheduled task for beep event */
 };