dt-bindings: hwmon: sparx5: use correct clock

SparX-5 temperature sensor uses system reference clock and not the AHB bus
clock as indicated by the register information [1].

So, correct the clock description as well the included example.

[1] https://microchip-ung.github.io/sparx-5_reginfo/reginfo_sparx-5.html?select=hsiowrap,temp_sensor,temp_sensor_cfg,clk_cycles_1us

Fixes: f5520753c16f ("dt-bindings: hwmon: Add Sparx5 temperature sensor")
Signed-off-by: Robert Marko <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/devicetree/bindings/hwmon/microchip,sparx5-temp.yaml

···
 
   clocks:
     items:
-      - description: AHB reference clock
+      - description: System reference clock
 
   '#thermal-sensor-cells':
     const: 0
···
         compatible = "microchip,sparx5-temp";
         reg = <0x10508110 0xc>;
         #thermal-sensor-cells = <0>;
-        clocks = <&ahb_clk>;
+        clocks = <&sys_clk>;
     };