msm: mdss: support mdp prefill bandwith for multiple platforms

To calculate mdp prefill bandwidth, mdp driver needs to get h/w
dependent buffer constants from device tree. Also add h/w feature
dependent logic.

Change-Id: I8d56ec502a6fd56eaae5b65a326ef966be46f14b
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>