drm/omap: Whitelist DT nodes to fixup with omapdss, prefix

The omapdss driver patches DT at runtime to prepend an "omapdss," prefix
to the compatible string of all encoders, panels and connectors. This
mechanism ensures they get bound to the omapdss-specific drivers instead
of generic drivers.

Now that we have drm_bridge support in omapdrm, we need to selectively
disable this mechanism. Add a whitelist of compatible strings to patch,
and fill it with all the devices we support. They will be removed one by
one once corresponding drm_bridge drivers become available and get
successfully tested with omapdrm.

The omapdss components load check code is updated accordingly to ignore
devices managed by external bridge drivers.

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>