ASoC: SOF: ipc4-topology: Fix input format query of process modules without base extension

If a process module does not have base config extension then the same
format applies to all of it's inputs and the process->base_config_ext is
NULL, causing NULL dereference when specifically crafted topology and
sequences used.

Fixes: 648fea12 ("ASoC: SOF: ipc4-topology: set copier output format for process module")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://msgid.link/r/20240529121201.14687-1-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/ipc4-topology.c

@@ -217,6 +217,14 @@ sof_ipc4_get_input_pin_audio_fmt(struct snd_sof_widget *swidget, int pin_index)
 	}
 
 	process = swidget->private;
+
+	/*
+	 * For process modules without base config extension, base module config
+	 * format is used for all input pins
+	 */
+	if (process->init_config != SOF_IPC4_MODULE_INIT_CONFIG_TYPE_BASE_CFG_WITH_EXT)
+		return &process->base_config.audio_fmt;
+
 	base_cfg_ext = process->base_config_ext;
 
 	/*