ASoC: Intel: Remove SST firmware components

sst-firmware is host to many image loading over DMA operations. Majority
of code targets sound/soc/intel/haswell solution as /baytrail/ never
switched to DMA-based firmware loading. With /haswell/ removed this code
serves no purpose. Address this redundancy.

Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Liam Girdwood <liam.r.girdwood@intel.com>
Link: https://lore.kernel.org/r/20201006064907.16277-7-cezary.rojewski@intel.com


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