dmaengine: mmp_tdma: add mmp tdma support

Add support for two-channel dma under dmaengine
support: mmp-adma and pxa910-squ

Signed-off-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Leo Yan <leoy@marvell.com>
Signed-off-by: Qiao Zhou <zhouqiao@marvell.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>