dt-bindings: phy: Add USB PHY support for Intel LGM SoC

Add the dt-schema to support USB PHY on Intel LGM SoC

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200828022312.52724-2-vadivel.muruganx.ramuthevar@linux.intel.com


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