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 assist dma transfers.
This hardware needs to be setup before any dma transfer is requested.
DML itself is not a DMA engine, its just a gule between the SD card
controller and dma controller.

Most of this code has been ported from qualcomm's 3.4 kernel.

This patch adds the code necessary to intialize the hardware and setup
before doing any dma transfers.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>