ASoC: mfld-compress: Use dedicated function instead of ioctl

Also pass sst device as an argument to function pointer prototypes of
compr_ops. This will be used to derive sst driver context.

Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>