dt-binding: phy: convert ti,omap-usb2 to YAML

Move ti,omap-usb2 to its own YAML schema.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200831142130.21836-1-rogerq@ti.com


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