mfd: dt-bindings: google,cros-ec: Fix indentation in example

Correct level of indentation in the example.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/mfd/google,cros-ec.yaml

···
             spi-max-frequency = <5000000>;
 
             proximity {
-                    compatible = "google,cros-ec-mkbp-proximity";
+                compatible = "google,cros-ec-mkbp-proximity";
             };
 
             cbas {