dt-bindings: usb: atmel: add USB PHY type property

Add USB PHY type property for controllers with HSIC support.

Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Link: https://lore.kernel.org/r/20210910163842.1596407-2-cristian.birsan@microchip.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>