msm: mdss: Increase the cnoc clock rate

Higher cnoc clock rate is required in order to fix very slow register
accesses issue. This is done by piggybacking on bus bandwidth requests by
voting on cnoc frequency when any bus bandwidth is requested, meaning
MDP is active.

Change-Id: I040d9ccdfa9c7b420ecf74e97b80ce305eae4c4f
Signed-off-by: Ping Li <quicpingli@codeaurora.org>