ASoC: SOF: remove several superfluous type-casts

ASoC: SOF: remove several superfluous type-casts

No need to type-cast assignments between void and other pointers in C.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200917105633.2579047-7-kai.vehmanen@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>