arm64: dts: qcom: sc7280: Add DSI display nodes

Add DSI controller and PHY nodes for sc7280.

Signed-off-by: Rajeev Nandan <quic_rajeevny@quicinc.com>
Signed-off-by: Krishna Manikandan <quic_mkrishn@quicinc.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1640361793-26486-3-git-send-email-quic_sbillaka@quicinc.com