Revert "msm: mdss: Override partial update PP block using ioctl"

This reverts commit 679dc362a9effee922ef2ce1447424b318f667bc.
The way overriding partial update via PP ioctl is obsolete,
partial update control is going through sysfs. The left code
is blocking pp ioctl even partial update is disabled dynamically.

Change-Id: Icb455a0101b53c58ae6c1b2686bd2297b4832396
Signed-off-by: Ken Zhang <kenz@codeaurora.org>
Signed-off-by: Ping Li <pingli@codeaurora.org>