ARM: dts: msm: Populate OPP table for GFX clock on MSM8917

For GPU thermal mitigation, there is need to populate OPP
table for gfx3d clock source so add support for the same.

Change-Id: Ib1fe1281b50a87d7fdb11545765485dc2a231d1e
Signed-off-by: Diptanshu Jamgade <djamgade@codeaurora.org>