ASoC: SOF: Intel: hda-loader-skl: Use the basefw firmware container directly

Switch to access to the firmware struct via sdev->basefw container to
unblock the removal of the firmware information from plat_data.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Chao Song <chao.song@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20221020121238.18339-6-peter.ujfalusi@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>