ARM: dts: msm: Add device tree support for SDA670

Add device tree files for sda670 SoC based platforms.
Add device tree files for their overlay support
as well.

Change-Id: Idd5db1b5967f79f7a1f55cb19e76cd8c23e78056
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>