dt-bindings: pinctrl: aspeed,ast2600-pinctrl: add NCSI groups

In the NCSI pin table, the reference clock output pin (RMIIXRCLKO) is not
needed on the management controller side.

Add "NCSI" pin groups that are equivalent to the RMII pin groups, but
without the RMIIXRCLKO pin.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Potin Lai <potin.lai.pt@gmail.com>
Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Link: https://lore.kernel.org/20240621093142.698529-2-potin.lai.pt@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: potinlai

Documentation/devicetree/bindings/pinctrl/aspeed,ast2600-pinctrl.yaml

@@ -19,6 +19,11 @@ description: |+
   Refer to the bindings described in
   Documentation/devicetree/bindings/mfd/syscon.yaml
 
+  Note: According to the NCSI specification, the reference clock output pin
+  (RMIIXRCLKO) is not required on the management controller side. To optimize
+  pin usage, add "NCSI" pin groups that are equivalent to the RMII pin groups,
+  but without the RMIIXRCLKO pin.
+
 properties:
   compatible:
     const: aspeed,ast2600-pinctrl
@@ -337,6 +342,8 @@ additionalProperties:
         - MDIO2
         - MDIO3
         - MDIO4
+        - NCSI3
+        - NCSI4
         - NCTS1
         - NCTS2
         - NCTS3