ALSA: hda - add a new condition to check if it is thinkpad

commit 2ecb704a upstream.

Latest Thinkpad laptops use the HKEY_HID LEN0268 instead of the
LEN0068, as a result neither audio mute led nor mic mute led can work
any more.

After adding the new HKEY_HID into the is_thinkpad(), both of them
works well as before.
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.16: use acpi_get_devices() instead of acpi_dev_found()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

sound/pci/hda/thinkpad_helper.c

@@ -26,6 +26,9 @@ static bool is_thinkpad(struct hda_codec *codec)
 	if (ACPI_SUCCESS(acpi_get_devices("LEN0068", acpi_check_cb, &found, NULL)) && found)
 		return true;
 	found = false;
+	if (ACPI_SUCCESS(acpi_get_devices("LEN0268", acpi_check_cb, &found, NULL)) && found)
+		return true;
+	found = false;
 	return ACPI_SUCCESS(acpi_get_devices("IBM0068", acpi_check_cb, &found, NULL)) && found;
 }