Add missing error handling in bind().

Fixes: 412d4ae6 ("drm/rockchip: hdmi: add Innosilicon HDMI support")
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
[moved clk_disable_unprepare reordering in unbind to separate patch]
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/20180302175757.28192-3-enric.balletbo@collabora.com