dt-bindings: net: dsa: microchip: add wakeup-source property

Add wakeup-source property to enable Wake on Lan functionality in the
switch.

Since PME wake pin is not always attached to the SoC, use wakeup-source
instead of wakeup-gpios
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml

@@ -38,6 +38,8 @@ properties:
       Should be a gpio specifier for a reset line.
     maxItems: 1
 
+  wakeup-source: true
+
   microchip,synclko-125:
     $ref: /schemas/types.yaml#/definitions/flag
     description: