OMAPDSS: Add overlay manager width and height limits as a dispc feature

The overlay manager width and height vary in OMAP5 from previous OMAPs
in terms of maximum limit and register field positions. Add parameters
in dispc_features for these. Also remove params related to manager width
and height from dss_features, as we want to maintain a feature list for
individual IPs.

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