ASoC: imx-ssi: Set dma data early

Move the call to snd_soc_dai_set_dma_data from the hw_params callback to the
startup callback. This allows us to use the dma data in the pcm driver's open
callback.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>