arm64: dts: qcom: sc7180: Avoid "phy" for USB QMP PHY wrapper

The bindings for the QMP PHY are truly strange.  I believe (?) that
they may have originated because with PCIe each lane is treated as a
different PHY and the same PHY driver is used for a whole bunch of
things (incluidng PCIe).

In any case, now that we have "make dtbs_check", we find that having
the outer node named "phy" triggers the
"schemas/phy/phy-provider.yaml" schema, yelling about:

  phy@88e9000: '#phy-cells' is a required property

Let's call the outer node the "phy-wrapper" and the inner node the
"phy" to make dtbs_check happy.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Fixes: 0b766e7f ("arm64: dts: qcom: sc7180: Add USB related nodes")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191212113540.6.Iec10b23bb000186b36b8bacfb6789d8233de04a7@changeid


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>