ARM: dts: msm: Add SPS node for SDM640

Add SPS module to device tree. SPS (Smart Peripheral System)
enables the support of all BAMs in the system which provide DMA
functionality to various peripherals.

Change-Id: I9fd43cd9f2f7f7fa1831283116c6bb0041fbc914
Signed-off-by: Jishnu Prakash <jprakash@codeaurora.org>