ASoC: Intel: remove conflicts when load/unload multiple firmware images

Details:
  1. Unload all modules on fw_list of dsp when suspend, and reload all
modules on fw_list when resume.
  2. A DSP expects only one scratch, but hsw_parse_fw_image() allocates
scratch blocks for each firmware image it parses. Move the allocate function
sst_block_alloc_scratch() out of hsw_parse_fw_image() to make sure a scratch
be allocated only after all firmware images be parsed.

Signed-off-by: Lu, Han <han.lu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>