ASoC and non-ASoC drivers for PCM DMA on PXA share lots of common code.
Move it to pxa2xx-lib.

[Fixed some checkpatch warnings -- broonie]
Signed-off-by: NDmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>