dt-bindings: net: dsa: microchip: add microchip,pme-active-high flag

Add microchip,pme-active-high property to set the PME (Power
Management Event) pin polarity for Wake on Lan interrupts.

Note that the polarity is active-low by default.
Signed-off-by: Pieter Van Trappen <pieter.van.trappen@cern.ch>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20240813142750.772781-2-vtpieter@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -51,6 +51,11 @@ properties:
       Set if the output SYNCLKO clock should be disabled. Do not mix with
       microchip,synclko-125.
 
+  microchip,pme-active-high:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Indicates if the PME pin polarity is active-high.
+
   microchip,io-drive-strength-microamp:
     description:
       IO Pad Drive Strength