dmaengine: s3c24xx-dma: Add cyclic transfer support

Many audio interface drivers require support of cyclic transfers to work
correctly, for example Samsung ASoC DMA driver. This patch adds support
for cyclic transfers to the s3c24xx-dma driver

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>