Revert "ARM: dts: msm: Report GPU chipID as A615 on SDM710"

This reverts commit b0a7b865
which was a temporary change to report GPU chipID as A615 on
SDM710 due to unavailability of userspace changes. With this
revert, GPU chipID will be reported as A616.

Change-Id: I22ddff22bfce1a10cfb2e5cae75b6fc4bf7404a3
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>