Revert "msm8974: Temporarily disable partial display updates"

This reverts commit a386e236d1091f789bb5677b4e67cce29eee9f84.

Change-Id: I3f1ad1ce7e5641c8c0c96956ba495ba115fa3eaf
msm: mdss: add support to validate pixel extension calculations

If a layer needs a scaling than its pixel extension values are calculated
in the user-space library and passed down to driver. Currently driver
blindly programs these settings to HW without validating for correctness.
This leads to HW hangs and stability issues. Add a proper sanitization
checks for pixel extension and report error back to user-space if any.

Change-Id: I086cf0b23fbccd37a23bb509f067bffdf396c247
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>

msm: mdss: fix bug for validating pixel extension calculations

While validating pixel extension calculations from user space,
validate the over fetch pixels with image dimentions in both
horizontal and vertical directions.

Change-Id: I8e39e89d9ace8e26237b3b23ca375456abd804a1
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>