drm/bridge: lt9611: fix sleep mode setup

drm/bridge: lt9611: fix sleep mode setup

[ Upstream commit ae2d329f104b75a0a78dcaded29fe6283289cdf9 ]

On atomic_post_disable the bridge goes to the low power state. However
the code disables too much of the chip, so the HPD event is not being
detected and delivered to the host. Reduce the power saving in order to
get the HPD event.

Fixes: 23278bf54afe ("drm/bridge: Introduce LT9611 DSI to HDMI bridge")
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230118081658.2198520-2-dmitry.baryshkov@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>