drm/rockchip: dw-mipi-dsi: Fix connector and encoder cleanup.

In bind()'s error handling path call destroy functions instead of
cleanup functions for encoder and connector and reorder to match how is
called in bind().

In unbind() call the connector and encoder destroy functions.

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180302175757.28192-2-enric.balletbo@collabora.com