drm/bridge: tc358767: read display_props in get_modes()

We need to know the link bandwidth to filter out modes we cannot
support, so we need to have read the display props before doing the
filtering.

To ensure we have up to date display props, call tc_get_display_props()
in the beginning of tc_connector_get_modes().

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528082747.3631-22-tomi.valkeinen@ti.com