ALSA: hda - Allow jack detection when polling is enabled

Let is_jack_detectable() return true when the jack polling is enabled
for the codec.  VT1708 uses the polling explicitly so we need to allow
it.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_jack.c b/sound/pci/hda/hda_jack.c
index 6479b65..1d035ef 100644
--- a/sound/pci/hda/hda_jack.c
+++ b/sound/pci/hda/hda_jack.c
@@ -29,7 +29,8 @@
 	if (get_defcfg_misc(snd_hda_codec_get_pincfg(codec, nid)) &
 	     AC_DEFCFG_MISC_NO_PRESENCE)
 		return false;
-	if (!(get_wcaps(codec, nid) & AC_WCAP_UNSOL_CAP))
+	if (!(get_wcaps(codec, nid) & AC_WCAP_UNSOL_CAP) &&
+	    !codec->jackpoll_interval)
 		return false;
 	return true;
 }