dt-bindings: display/msm: dp-controller: document DP on SM7150

dt-bindings: display/msm: dp-controller: document DP on SM7150

The qcom,sm7150-dp compatible is documented in schema. Mark DisplayPort
controller as compatible with SM8350.

Fixes: 726eded12dd7 ("dt-bindings: display/msm: Add SM7150 MDSS")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Patchwork: https://patchwork.freedesktop.org/patch/672572/
Link: https://lore.kernel.org/r/20250903-dp_mst_bindings-v8-3-7526f0311eaa@oss.qualcomm.com