dt-bindings: display/msm: dp-controller: allow eDP for SA8775P

dt-bindings: display/msm: dp-controller: allow eDP for SA8775P

On Qualcomm SA8775P the DP controller might be driving either a
DisplayPort or a eDP sink (depending on the PHY that is tied to the
controller). Reflect that in the schema.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/672569/
Link: https://lore.kernel.org/r/20250903-dp_mst_bindings-v8-1-7526f0311eaa@oss.qualcomm.com