drm/omap: Merge display .get_modes() and .get_size() operations

drm/omap: Merge display .get_modes() and .get_size() operations

Now that the .get_modes() operations takes a drm_connector and fills it
with modes, it becomes easy to fill display information in the same
operation without requiring a separate .get_size() opearation.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>