arm64: dts: qcom: sc7280: drop unused clocks from eDP node

The eDP node includes two clocks which are used by the eDP PHY rather
than eDP controller itself. Drop these clocks to remove extra difference
between eDP and DP controllers.

Suggested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220710084133.30976-7-dmitry.baryshkov@linaro.org