ASoC: SOF: imx: Do not set fw_ready callback

ASoC: SOF: imx: Do not set fw_ready callback

The fw_ready is handled internally to ipc3 and the callback no longer in
use.

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: Ajit Pandey <ajitkumar.pandey@amd.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Link: https://lore.kernel.org/r/20220421080735.31698-5-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>