ARM: dts: msm: Set VBIF based GPU bus governor as default for MSM8994

Use bw_vbif governor to vote for GPU msm bus bandwidth.

Change-Id: Ib7bf061b9c4eb8d23a0e6670fb7e18ba1d8c764b
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>