dt-bindings: phy: qcom,sc8280xp-qmp-usb3-uni: Add SA8775P USB PHY binding

Add compatible string for Qualcomm QMP Super Speed (SS) UNI PHY found
in SA8775P.

Signed-off-by: Shazad Hussain <quic_shazhuss@quicinc.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230428130824.23803-4-quic_shazhuss@quicinc.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>