msm8974: Fix a screen corruption issue

 * Diogo noticed that Facebook's popups were leaving artifacts
   when you moved them around.
 * Adjust the partial-update ROI alignment to compensate for
   this case.

Change-Id: I2f57b0b17596dabdae89b173e0b932959ceb1db4
Merge "msm8974: Fix a screen corruption issue" into kitkat