ASoC: qdsp6: audioreach: add basic pkt alloc support

Add basic helper functions for AudioReach.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20211026111655.1702-10-srinivas.kandagatla@linaro.org


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