mmc: mmci: Add qcom dml support to the driver.

On Qualcomm APQ8064 SOCs, SD card controller has an additional glue
called DML (Data Mover Local/Lite) to do dma transfers between
Controller and DMA engine. This hardware needs to be setup before any
dma transfer is requested.
This patch adds the code necessary to intialize the hardware and setup
before doing any dma transfers.

Please Note: this is a just a first version of the patch, so there is a
scope of improvement on this.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>