Provides a V4L2 device that uses the MDP overlay pipes (on MDP4), or the PPP interface (MDP3) to overlay frames on top of display framebuffer. Signed-off-by: Alhad Purnapatre <alhadp@codeaurora.org> Change-Id: Iab69d0a5acfe993d13cb7a585e292b9a87eb90ee