dt-bindings: display: msm: dp-controller: document SM6350 compatible

Add the compatible string for the DisplayPort controller on SM6350 which
is compatible with the one on SM8350.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Patchwork: https://patchwork.freedesktop.org/patch/585469/
Link: https://lore.kernel.org/r/20240329-sm6350-dp-v2-1-e46dceb32ef5@fairphone.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>