ARM: dts: msm: Add initial device tree for SDM660

Add initial device tree support for SDM660
This is a snapshot of dtsi files as of msm-4.4
'commit c2f54771deefa34bf (" Merge "ion:
ion_system_heap: Fix variable initialization"").

Change-Id: Id87712c6cfffe6032daf4c0e3b52dc33ae1ae09d
Signed-off-by: Naitik Bharadiya <bharad@codeaurora.org>
Signed-off-by: Chetan C R <cchinnad@codeaurora.org>