OMAPDSS: TFP410: fix input sync signals

TFP410 requires that DE is active high and the data and syncs are driven
on rising pixel clock edge. However, at the moment the driver doesn't
request such syncs, and the end result is that the sync settings depend
on default values, which are not right in all cases.

Set the sync values explicitly.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>