drm: Config orientation property if panel provides it

Panel orientation property should be set before drm_dev_register().
Some drm driver calls drm_dev_register() in .bind(). However, most
panels sets orientation property relatively late, mostly in .get_modes()
callback, since this is when they are able to get the connector and
binds the orientation property to it, though the value should be known
when the panel is probed.

In drm_bridge_connector_init(), if a bridge is a panel bridge, use it to
set the connector's panel orientation property.

Suggested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
[dianders: fixed space vs. tab indentation]
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220609072722.3488207-9-hsinyi@chromium.org