ALSA: hda - More kerneldoc comments

Put more kerneldoc comments to the exported functions.
Still the generic parser code and the HD-audio controller code aren't
covered yet, though.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_jack.h b/sound/pci/hda/hda_jack.h
index 13cb375..b279e32 100644
--- a/sound/pci/hda/hda_jack.h
+++ b/sound/pci/hda/hda_jack.h
@@ -72,6 +72,11 @@
 
 int snd_hda_jack_detect_state(struct hda_codec *codec, hda_nid_t nid);
 
+/**
+ * snd_hda_jack_detect - Detect the jack
+ * @codec: the HDA codec
+ * @nid: pin NID to check jack detection
+ */
 static inline bool snd_hda_jack_detect(struct hda_codec *codec, hda_nid_t nid)
 {
 	return snd_hda_jack_detect_state(codec, nid) != HDA_JACK_NOT_PRESENT;