ARM: dts: msm: Add GPU properties for SDM670 GPU

Add initial version of SDM670 GPU properties.

This is needed to support Graphics driver functionality
on SDM670 target.

Change-Id: Ia879e4b4c6d9d242b9e7bb4f7af6e8b368149733
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>