Clean up the DISPC manager timings related function by:

- Create a common function to set size for LCD and TV.
- Create a common function to check timings for LCD and TV.
- Add dss params to get the range of manager size.

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