ASoC: ux500: Move DMA parameters into ux500_msp

Move struct ux500_msp_dma_params declaration from ux500_msp_i2s_drvdata
to ux500_msp, this saves some confusing pointer passing and allows to
access all DMA configuration fields from ux500_msp_i2s.

Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>