drm/omap: Pass drm_display_mode to .check_timings() and .set_timings()

drm/omap: Pass drm_display_mode to .check_timings() and .set_timings()

The omap_dss_device .check_timings() and .set_timings() operations
operate on struct videomode, while the DRM API operates on struct
drm_display_mode. This forces conversion from to videomode in the
callers. While that's not a problem per se, it creates a difference with
the drm_bridge API.

Replace the videomode parameter to the .check_timings() and
.set_timings() operations with a drm_display_mode. This pushed the
conversion to videomode down to the DSS devices in some cases. If needed
they will be converted to operate on drm_display_mode natively.

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>