drm/bridge: anx7625: keep last configure timing

Sometimes kernel may resume back quickly after suspend,
and DRM not call .mode_set() to re-config
display timing before calling .atomic_enable(), bridge
driver with this patch to keep last configure timing.

Signed-off-by: Xin Ji <xji@analogixsemi.com>
Acked-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221209030418.713935-1-xji@analogixsemi.com