ARM: dts: msm: Add device tree for MPQ8092 DMA

Add a DTSI file and a top-level DTS file needed to support
the MPQ8092 DMA platform in a dedicated DTS file.

Change-Id: If5483e6fe389f3d8880152cdd95e43331a65c108
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>