ALSA: hda/tas2781: properly initialize speaker_id for TAS2563

After speaker id retrieval was refactored to happen in tas2781_read_acpi,
devices that do not use a speaker id need a negative speaker_id value
instead of NULL, but no initialization was added to the TAS2563 code path.
This causes the driver to attempt to load a non-existent firmware file name
with a speaker id of 0 ("TAS2XXX38700.bin") instead of the correct file
name without a speaker id ("TAS2XXX3870.bin"), resulting in low volume and
these dmesg errors:

    tas2781-hda i2c-INT8866:00: Direct firmware load for TAS2XXX38700.bin failed with error -2
    tas2781-hda i2c-INT8866:00: tasdevice_dsp_parser: load TAS2XXX38700.bin error
    tas2781-hda i2c-INT8866:00: dspfw load TAS2XXX38700.bin error
    [...]
    tas2781-hda i2c-INT8866:00: tasdevice_prmg_load: Firmware is NULL

Fix this by setting speaker_id to -1 as is done for other models.

Fixes: 945865a ("ALSA: hda/tas2781: fix speaker id retrieval for multiple probes")
Cc: stable@vger.kernel.org
Signed-off-by: August Wikerfors <git@augustwikerfors.se>
Link: https://patch.msgid.link/20251222194704.87232-1-git@augustwikerfors.se
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Author: 0x9fff00

sound/hda/codecs/side-codecs/tas2781_hda_i2c.c

@@ -111,8 +111,10 @@ static int tas2781_read_acpi(struct tasdevice_priv *p, const char *hid)
 	sub = acpi_get_subsystem_id(ACPI_HANDLE(physdev));
 	if (IS_ERR(sub)) {
 		/* No subsys id in older tas2563 projects. */
-		if (!strncmp(hid, "INT8866", sizeof("INT8866")))
+		if (!strncmp(hid, "INT8866", sizeof("INT8866"))) {
+			p->speaker_id = -1;
 			goto end_2563;
+		}
 		dev_err(p->dev, "Failed to get SUBSYS ID.\n");
 		ret = PTR_ERR(sub);
 		goto err;