arm64: dts: qcom: sc7180: change DSI PHY node name to generic one

Change DSI PHY node names from custom 'dsi-phy' to the generic 'phy'.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220924090108.166934-6-dmitry.baryshkov@linaro.org