In order to check the validity of overlay and manager info, there was a need to
use the omap_dss_device struct to get the panel resolution. The manager's
private data in APPLY now contains the manager timings. Hence, we don't need to
rely on the display resolution any more.

Pass the manager's timings in private data to dss_mgr_check(). Remove the need
to pass omap_dss_device structs in the functions which check for the validity
of overlay and manager parameters.
Signed-off-by: Archit Taneja <archit@ti.com>