dt-bindings: phy: Convert motorola,mapphone-mdm6600 to DT schema

Convert the Motorola Mapphone MDM6600 USB PHY binding to DT schema
format. It's a straight forward conversion.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250607212621.743859-1-robh@kernel.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>