[ALSA] ASoC Samsung S3C24xx audio DMA

This patch by Ben Dooks from Simtec Electronics adds ASoC audio DMA
support for the Samsung S3C24xx CPU.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>