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.

Conflicts:

	drivers/video/msm/mdss/mdss.h

Change-Id: I8d56ec502a6fd56eaae5b65a326ef966be46f14b
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>
msm: mdss: reduce mdp prefill bandwidth vote for command mode panel

The current result of mdp prefill bandwidth calculation for command
mode is larger than what is actually needed for many use cases. This
is due to the fact that for command mode panels during prefill time,
there are less buffer prefill requirement or time constraint than that
of video panels. This patch makes adjustment accordingly based on the
updated equations by h/w team.

Change-Id: I06935a29d771202b3f8dc2c62cf948a8ecc81481
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>