ASoC: Intel: broadwell: Simplify device probe

With legacy ADSP private context adjusted, there is no need for double
safety.

Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20190822113616.22702-5-cezary.rojewski@intel.com


Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>