dt-bindings: pinctrl: ocelot: add lan966x SoC support

Add documentation for the compatible designated for lan966x.
Signed-off-by: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211118112548.14582-2-kavyasree.kotagiri@microchip.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/mscc,ocelot-pinctrl.txt

@@ -4,7 +4,8 @@ Microsemi Ocelot pin controller Device Tree Bindings
 Required properties:
  - compatible		: Should be "mscc,ocelot-pinctrl",
 			  "mscc,jaguar2-pinctrl", "microchip,sparx5-pinctrl",
-			  "mscc,luton-pinctrl" or "mscc,serval-pinctrl"
+			  "mscc,luton-pinctrl", "mscc,serval-pinctrl" or
+			  "microchip,lan966x-pinctrl"
  - reg			: Address and length of the register set for the device
  - gpio-controller	: Indicates this device is a GPIO controller
  - #gpio-cells		: Must be 2.