dt-bindings: phy: qcom,qusb2: Convert QUSB2 phy bindings to yaml

Convert QUSB2 phy  bindings to DT schema format using json-schema.

Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>