arm64: dts: qcom: sc8280xp: drop broken DP PHY nodes

The DP PHY register layout of the current binding do not apply to the
newer USB4/USB3/DP PHY which uses a different register layout entirely.

Drop the DP PHY subnodes until the binding has been updated to prevent
the driver from corrupting unrelated registers.

Note that this is also needed in order to not break USB with an upcoming
PHY driver change that checks for overlapping register regions.

Fixes: 152d1faf ("arm64: dts: qcom: add SC8280XP platform")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220919094454.1574-5-johan+linaro@kernel.org