ASoC: amd: dma config parameters changes

Added dma configuration parameters to rtd structure.
Moved dma configuration parameters initialization to
hw_params callback.
Removed hard coding in prepare and trigger callbacks.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>