dt-bindings: pse: tps23881: add reset-gpios

The TPS23881 has an active-low reset pin that can be connected to an
SoC.  Document this with the device-tree binding.
Signed-off-by: Kyle Swenson <kyle.swenson@est.tech>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240822220100.3030184-2-kyle.swenson@est.techSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/devicetree/bindings/net/pse-pd/ti,tps23881.yaml

@@ -23,6 +23,9 @@ properties:
   '#pse-cells':
     const: 1
 
+  reset-gpios:
+    maxItems: 1
+
   channels:
     description: each set of 8 ports can be assigned to one physical
       channels or two for PoE4. This parameter describes the configuration