Add drm_panel controls to support powerup/down of the
eDP panel, if one is present at the sink side.
Signed-off-by: NAjay Kumar <ajaykumar.rs@samsung.com>
Acked-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>