drm/rockchip: dsi: Fix unbalanced clock on probe error

Our probe() function never enabled this clock, so we shouldn't disable
it if we fail to probe the bridge.

Noted by inspection.

Fixes: 2d4f7bda

 ("drm/rockchip: dsi: migrate to use dw-mipi-dsi bridge driver")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210928143413.v3.3.Ie8ceefb51ab6065a1151869b6fcda41a467d4d2c@changeid