ASoC: SOF: ipc-msg-injector: Query the maximum IPC payload size

ASoC: SOF: ipc-msg-injector: Query the maximum IPC payload size

Instead of using the SOF_IPC_MSG_MAX_SIZE as the maximum payload size for
and IPC message, use the provided API to query it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220506132647.18690-3-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>