ARM: dts: msm: Enable bus control for GPU on msm8909

Enabled bus control for GPU on msm8909 so that devfreq
governor is used to vote on behalf of GPU through bw
voting device gpubw-dev instead of GPU directly voting on
msm-bus through grp3d device.

Change-Id: I0a7dabdfd23f5a3122a270449ee1cc46f328847d
Signed-off-by: Archana Sriram <apsrir@codeaurora.org>