ASoC: SOF: ipc3: Implement the get_reply IPC ops

ASoC: SOF: ipc3: Implement the get_reply IPC ops

Add the implementation for the get_reply callback to copy the reply message
from mailbox to msg->reply_data buffer.

The implementation is equivalent to the currently used code in ipc.c

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://lore.kernel.org/r/20220405172708.122168-7-ranjani.sridharan@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>