ALSA: hda - Dell Studio 1557 hd-audio quirk

Add the Dell Studio 15 (model 1557, Core i7) laptop to the hd-audio
quirk list, enabling audio.

Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
index 8eb6508..86de305 100644
--- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -1590,6 +1590,8 @@
 				"Dell Studio 17", STAC_DELL_M6_DMIC),
 	SND_PCI_QUIRK(PCI_VENDOR_ID_DELL, 0x02be,
 				"Dell Studio 1555", STAC_DELL_M6_DMIC),
+	SND_PCI_QUIRK(PCI_VENDOR_ID_DELL, 0x02bd,
+				"Dell Studio 1557", STAC_DELL_M6_DMIC),
 	{} /* terminator */
 };