drm/bridge: tc358767: Add format negotiation hooks for DPI/DSI to (e)DP

commit e81cf1bec464e3b9bbdfb03f96a13b2f6c3577f3 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git



With new connector model, tc358767 will not create the connector, when
DRM_BRIDGE_ATTACH_NO_CONNECTOR is set and display-controller driver will
rely on format negotiation to setup the encoder format.

Add the missing bus format negotiation hooks in the
drm_bridge_funcs to complete DRM_BRIDGE_ATTACH_NO_CONNECTOR support.

Output format, for DPI/DSI to DP, is selected to
MEDIA_BUS_FMT_RGB888_1X24 as default, keeping in mind what the older
model used to support.

Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Closes: https://lore.kernel.org/all/24282420-b4dd-45b3-bb1c-fc37fe4a8205@siemens.com/


Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>