intel_mid: Add Mrst & Mfld DMA Drivers

This patch add DMA drivers for DMA controllers in Langwell chipset
of Intel(R) Moorestown platform and DMA controllers in Penwell of
Intel(R) Medfield platfrom

This patch adds support for Moorestown DMAC1 and DMAC2 controllers.
It also add support for Medfiled GP DMA and DMAC1 controllers.
These controllers supports memory to peripheral and peripheral to
memory transfers. It support only single block transfers.

This driver is based on Kernel DMA engine
Anyone who wishes to use this controller should use DMA engine APIs

This controller exposes DMA_SLAVE capabilities and notifies the client drivers
of DMA transaction completion

Config option required to be enabled CONFIG_INTEL_MID_DMAC=y

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>