ASoC: SOF: add IPC-dependent file names

To avoid misleading file names, use different names for INTEL_IPC4
firmware files.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Chao Song <chao.song@intel.com>
Link: https://lore.kernel.org/r/20220414184817.362215-5-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>