ASoC: samsung: remove unused DMA data

The s3c_dma_client structures and the 'ch' and 'ops' members in
s3c_dma_params were only used by the legacy DMA driver and serve
no function any more. This removes any reference to them.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@linaro.org>