drm/bridge: ti-sn65dsi83: Fix enable error path

If PLL locking failed, the regulator needs to be disabled again.

Fixes: 5664e3c9 ("drm/bridge: ti-sn65dsi83: Add vcc supply regulator support")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230504065316.2640739-1-alexander.stein@ew.tq-group.com