arm64: dts: qcom: sc8280xp-x13s: Enable external display

Like on the CRD, add the necessary nodes to enable USB Type-C
altmode-based external display on the Lenovo ThinkPad X13s.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213215619.1362566-4-quic_bjorande@quicinc.com