dt-bindings: clock: mediatek: Document reset cells for MT8188 sys

The MT8188 sys clocks embed a reset controller: add #reset-cells
to the binding to allow using resets.

Fixes: 1086a531 ("dt-bindings: clock: mediatek: Add new MT8188 clock")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240619085322.66716-2-angelogioacchino.delregno@collabora.comAcked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/mediatek,mt8188-sys-clock.yaml

@@ -39,6 +39,9 @@ properties:
   '#clock-cells':
     const: 1
 
+  '#reset-cells':
+    const: 1
+
 required:
   - compatible
   - reg