dt-bindings: clock: mediatek,mt7621-sysc: add '#reset-cells' property

Make system controller a reset provider for all the peripherals in the
MT7621 SoC adding '#reset-cells' property.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20220210094859.927868-2-sergio.paracuellos@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/clock/mediatek,mt7621-sysc.yaml

@@ -22,6 +22,11 @@ description: |
 
   The clocks are provided inside a system controller node.
 
+  This node is also a reset provider for all the peripherals.
+
+  Reset related bits are defined in:
+  [2]: <include/dt-bindings/reset/mt7621-reset.h>.
+
 properties:
   compatible:
     items:
@@ -37,6 +42,12 @@ properties:
       clocks.
     const: 1
 
+  "#reset-cells":
+    description:
+      The first cell indicates the reset bit within the register, see
+      [2] for available resets.
+    const: 1
+
   ralink,memctl:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
@@ -61,6 +72,7 @@ examples:
       compatible = "mediatek,mt7621-sysc", "syscon";
       reg = <0x0 0x100>;
       #clock-cells = <1>;
+      #reset-cells = <1>;
       ralink,memctl = <&memc>;
       clock-output-names = "xtal", "cpu", "bus",
                            "50m", "125m", "150m",