msm: mdss: allow assertive display on write back framebuffer

Reserve a mixer that supports AD to be used for write back and expose a
sysfs node for frame buffer devices which are able to support AD.

Change-Id: I0598a686d251444fc40bb8073ac50750036be7fe
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>
Signed-off-by: Sree Sesha Aravind Vadrevu <svadrevu@codeaurora.org>
Signed-off-by: Ping Li <quicpingli@codeaurora.org>
msm: mdss: Fix debugfs string overwrite

If more than one display paths are active, like split display or external
mirroring, and stat debugfs node is read then debug data for only one
display is shown. Fix this by using correct offsets.

Change-Id: Ia8b36eb3105f6df8f096ff544b82cc49c9b31a48
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>
msm: mdss: Initialize right mixer ROI for split control

This change initializes ROI of the right mixer on dual DSI panels
to its complete resolution. This will ensure that the right mixer
composes to its full resolution when partial update feature is not
enabled / applicable.

CRs-Fixed: 556185
Change-Id: I3c2f2b9a220dc223ef66475d6f6cbfc18c4a67db
Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>