Taking our cue from commit a42f6e3f ("drm/panel: simple: Add delay
timing for Sharp LQ123P1JX31"), let's add timings:

 .prepare = t1 + t3
 .enable = t7
 .unprepare = t11 + 12

Without this, the panel may not be given enough time to come up.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>