ASoC: SOF: Add IPC3 Kernel Injector

Add debugfs path to fake a malicious firmware message for fuzzing purposes.

Skip IPC4 for initial integration

Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230608221822.2825786-2-cujomalainey@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>