arm64: dts: qcom: sm6350: drop bogus DP PHY clock

The QMP pipe clock is used by the USB part of the PHY so drop the
corresponding properties from the DP child node.

Fixes: 23737b95 ("arm64: dts: qcom: sm6350: Add USB1 nodes")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221026152511.9661-3-johan+linaro@kernel.org