msm: mdss: update register list in support API

This change allows to read/write MDP ctl registers and flush
registers through ioctl. Changes are required to support
calibration tool.

Change-Id: Iabe6ae8d5214accf0dd61ff56b91270df4570af4
Signed-off-by: Arpita Banerjee <cabane@codeaurora.org>