dt-bindings: usb: microchip,usb5744: Add second supply

The USB5744 has two power supplies one for 3V3 and one for 1V2. Add the
second supply to the USB5744 DT binding.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20231113145921.30104-2-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>