ASoC: Intel: soc-acpi-intel-mtl-match: add missing empty item

There is no links_num in struct snd_soc_acpi_mach {}, and we test
!link->num_adr as a condition to end the loop in hda_sdw_machine_select().
So an empty item in struct snd_soc_acpi_link_adr array is required.

Fixes: f77ae7fc ("ASoC: Intel: soc-acpi-intel-mtl-match: add cs42l43 only support")
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://patch.msgid.link/20240906060224.2241212-3-yung-chuan.liao@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/common/soc-acpi-intel-mtl-match.c

@@ -674,6 +674,7 @@ static const struct snd_soc_acpi_link_adr mtl_cs42l43_l0[] = {
 		.num_adr = ARRAY_SIZE(cs42l43_0_adr),
 		.adr_d = cs42l43_0_adr,
 	},
+	{}
 };
 
 static const struct snd_soc_acpi_link_adr mtl_cs42l43_cs35l56[] = {