dt-bindings: mediatek: Add axi clock in mt8173 dts example

For mt8173, it is needed to add the axi clock for dma mode.
Signed-off-by: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220725120204.10834-1-xiangsheng.hou@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml

@@ -85,8 +85,9 @@ examples:
         compatible = "mediatek,mt8173-nor";
         reg = <0 0x1100d000 0 0xe0>;
         interrupts = <1>;
-        clocks = <&pericfg CLK_PERI_SPI>, <&topckgen CLK_TOP_SPINFI_IFR_SEL>;
-        clock-names = "spi", "sf";
+        clocks = <&pericfg CLK_PERI_SPI>, <&topckgen CLK_TOP_SPINFI_IFR_SEL>,
+                 <&pericfg CLK_PERI_NFI>;
+        clock-names = "spi", "sf", "axi";
         #address-cells = <1>;
         #size-cells = <0>;