dt-bindings: usb: ti,omap4-musb: Drop duplicate 'usb-phy' property constraints

dt-bindings: usb: ti,omap4-musb: Drop duplicate 'usb-phy' property constraints

The deprecated 'usb-phy' property is documented already in usb.yaml and
doesn't need a type definition here. It just needs constraints on how
many entries there are.

As this is a host controller, reference usb-hcd.yaml which then
references usb.yaml.

Fixes: 70fcdc82cf4a ("dt-bindings: usb: ti,omap4-musb: convert to DT schema")
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260508182556.1759173-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>