ASoC: SOF: amd: acp-pcm: Take buffer information directly from runtime

ASoC: SOF: amd: acp-pcm: Take buffer information directly from runtime

Instead of using the values from ipc_params, take them directly from
substream->runtime.

This is in preparation of making the platform hw_params callback to be
IPC agnostic.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220304205733.62233-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>