OMAPDSS: HDMI: change the timing match logic

Change the timing match logic, Instead of the statically mapped method
to get the corresponding timings for a given code and mode, move to a
simpler array indexed method. It  will help to scale up to add more
timings when needed.

Signed-off-by: Mythri P K <mythripk@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>