DSI video mode engine can only take active-high sync signals. This
change prevents MDP5 sending active-low sync signals to DSI in any
case.
Signed-off-by: NHai Li <hali@codeaurora.org>
Tested-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NRob Clark <robdclark@gmail.com>