OMAP: DSS2: TDO35S: fix video signaling

TDO35S samples the data on the falling adge of the pixel clock,
therefore the data strobe should be on the raising edge.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>