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.com


Signed-off-by: Mark Brown <broonie@kernel.org>