arm64: dts: qcom: sc8280xp: drop UFS PHY clock-cells

The QMP UFS PHY provides more than one symbol clock and would need an
index to differentiate the clocks, but none of this is described by the
binding currently.

Drop the incorrect '#clock-cells' property for now.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220705114032.22787-10-johan+linaro@kernel.org